RFC 8376
Low-Power Wide Area Network (LPWAN) Overview
Low-Power Wide Area Network (LPWAN) Overview 🦋
RFC 8376 🌸 by S. Farrell, Ed. from Trinity College Dublin, published in May 2018. It's an Informational doc, so it's for learning and background, not a standards-track spec. It also has an ISSN of 2070-1721. The header doesn't list any Obsoletes or Updates, so it doesn't replace or update any other RFCs. Bestie, this is the big picture on LPWANs, so let's go!! ✨
Abstract
Okay so, Low-Power Wide Area Networks (LPWANs) are wireless techs with some iconic traits: huge coverage areas, low bandwidth, possibly very tiny packets and app-layer data sizes, and super long battery life 🔋. This memo is an informational overview of the LPWAN techs the IETF is looking at, plus the gaps between what those techs need and the goal of running IP over LPWANs 💜.
Status of This Memo
This doc is not an Internet Standards Track specification. It's published just for info 🧚.
It's a product of the IETF, and it reflects the consensus of the IETF community. It got public review and was approved for publication by the Internet Engineering Steering Group (IESG). Not every IESG-approved doc is a candidate for any level of Internet Standard, so see Section 2 of RFC 7841 for that. 🫶
Info about the current status, any errata, and how to send feedback is at https://www.rfc-editor.org/info/rfc8376.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. 💅
This doc is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) as they stand on the publication date. Read those carefully, bestie, since they spell out your rights and restrictions for this doc. Code Components pulled out of this doc must include Simplified BSD License text, as described in Section 4.e of the Trust Legal Provisions, and they come with no warranty, as described in the Simplified BSD License. ⚖️
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. LPWAN Technologies . . . . . . . . . . . . . . . . . . . . . 3
2.1. LoRaWAN . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1. Provenance and Documents . . . . . . . . . . . . . . 4
2.1.2. Characteristics . . . . . . . . . . . . . . . . . . . 4
2.2. Narrowband IoT (NB-IoT) . . . . . . . . . . . . . . . . . 10
2.2.1. Provenance and Documents . . . . . . . . . . . . . . 10
2.2.2. Characteristics . . . . . . . . . . . . . . . . . . . 11
2.3. Sigfox . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.3.1. Provenance and Documents . . . . . . . . . . . . . . 15
2.3.2. Characteristics . . . . . . . . . . . . . . . . . . . 16
2.4. Wi-SUN Alliance Field Area Network (FAN) . . . . . . . . 20
2.4.1. Provenance and Documents . . . . . . . . . . . . . . 20
2.4.2. Characteristics . . . . . . . . . . . . . . . . . . . 21
3. Generic Terminology . . . . . . . . . . . . . . . . . . . . . 24
4. Gap Analysis . . . . . . . . . . . . . . . . . . . . . . . . 26
4.1. Naive Application of IPv6 . . . . . . . . . . . . . . . . 26
4.2. 6LoWPAN . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.2.1. Header Compression . . . . . . . . . . . . . . . . . 27
4.2.2. Address Autoconfiguration . . . . . . . . . . . . . . 27
4.2.3. Fragmentation . . . . . . . . . . . . . . . . . . . . 27
4.2.4. Neighbor Discovery . . . . . . . . . . . . . . . . . 28
4.3. 6lo . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.4. 6tisch . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.5. RoHC . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4.6. ROLL . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.7. CoAP . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.8. Mobility . . . . . . . . . . . . . . . . . . . . . . . . 31
4.9. DNS and LPWAN . . . . . . . . . . . . . . . . . . . . . . 31
5. Security Considerations . . . . . . . . . . . . . . . . . . . 31
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32
7. Informative References . . . . . . . . . . . . . . . . . . . 32
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 39
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 431. Introduction ✨
This doc gives background and an overview of the techs the IETF's IPv6 over Low Power Wide-Area Networks (LPWAN) Working Group (WG) is looking at. It also does a gap analysis between what those techs need and the IETF specs that already exist 🌈.
Most techs in this space are going for the same vibe: supporting huge numbers of very low-cost, low-throughput devices with very low power consumption, so even battery-powered gadgets can last for years 🔋. LPWAN devices are also pretty tight on bandwidth. For example, only limited frequencies may be used, and only within limited duty cycles (usually given as a percentage of time per hour that the device is allowed to transmit) ⏱️. Covering large areas is a shared goal too, which the name already tells you. So, by and large, these techs are aiming for deployments in very similar situations 🍓.
All constrained networks have to balance power consumption / battery life, cost, and bandwidth. LPWANs, though, put power and cost benefits first by accepting severe bandwidth and duty cycle constraints when making the required trade-offs. They make that call so they can get the multiple-kilometer radio links implied by "Wide Area" in LPWAN's name 📡.
Existing pilot deployments have shown huge potential and sparked lots of industry interest 🔥. At the time of writing, essentially no LPWAN end devices (other than for Wi-SUN) have IP capabilities. Connecting LPWANs to the Internet would bring real perks in interoperability, application deployment, and management (among others) 🫶. The LPWAN WG's goal is to, where necessary, adapt IETF-defined protocols, addressing schemes, and naming conventions to this particular constrained environment 💖.
This document is largely the work of the people listed in the Contributors section. Big thanks to them 👑.
2. LPWAN Technologies 🦋
This section gives an overview of the LPWAN techs being considered in the LPWAN WG. The text for each was mainly contributed by proponents of each tech 💅.
Note that this text is not intended to be normative in any sense. It just helps you find the relevant Layer 2 (L2) specs and understand how they integrate with IETF-defined technologies. There's also no attempt here to set out the pros and cons of the techs, so don't look for that here, bestie 🙈.
2.1. LoRaWAN 💜
2.1.1. Provenance and Documents
LoRaWAN is a wireless tech based on Industrial, Scientific, and Medical (ISM) bands. It's used for long-range, low-power, low-data-rate apps, and it was developed by the LoRa Alliance, a membership consortium <https://www.lora-alliance.org/>. This doc is based on Version 1.0.2 of the LoRa specification [LoRaSpec]. That spec is publicly available and has already seen several deployments across the globe 🌍.
2.1.2. Characteristics 🌈
LoRaWAN aims to support end devices running on a single battery for an extended period of time (e.g., 10 years or more). It also offers extended coverage through 155 dB maximum coupling loss, plus reliable and efficient file download (needed for remote software/firmware upgrades) 🔋✨.
LoRaWAN networks are usually organized in a star-of-stars topology. Gateways relay messages between end devices and a central "network server" in the backend. Gateways connect to the network server over IP links, while end devices use single-hop LoRaWAN communication that can be received at one or more Gateways. Communication is generally bidirectional, but uplink communication (from end devices to the network server) is favored because it has more overall bandwidth available 📶.
Figure 1 shows the entities involved in a LoRaWAN network 🧚:
+----------+
|End Device| * * *
+----------+ * +---------+
* | Gateway +---+
+----------+ * +---------+ | +---------+
|End Device| * * * +---+ Network +--- Application
+----------+ * | | Server |
* +---------+ | +---------+
+----------+ * | Gateway +---+
|End Device| * * * * +---------+
+----------+
Key: * LoRaWAN Radio
+---+ IP connectivity
Figure 1: LoRaWAN ArchitectureHere's the cast of characters:
- End Device: a LoRa client device, sometimes called a "mote". It communicates with Gateways. 📱
- Gateway: a radio on the infrastructure side, sometimes called a "concentrator" or "base station". It talks to end devices and, via IP, to a network server. 📡
- Network Server: The Network Server (NS) terminates the LoRaWAN Medium Access Control (MAC) layer for the end devices connected to the network. It's the center of the star topology. ⭐
- Join Server: The Join Server (JS) is a server on the Internet side of an NS that processes join requests from end devices. 🔑
- Uplink message: refers to communications from an end device to a network server or application via one or more Gateways. ⬆️
- Downlink message: refers to communications from a network server or application via one Gateway to a single end device or a group of end devices (considering multicasting). ⬇️
- Application: refers to application-layer code both on the end device and running "behind" the NS. For LoRaWAN, there will generally only be one application running on most end devices. Interfaces between the NS and the application aren't described further here. 💻
In LoRaWAN networks, end device transmissions may be received at multiple Gateways. So during nominal operation, a network server may see multiple copies of the same uplink message from an end device 👯.
The LoRaWAN network infrastructure manages the data rate and Radio Frequency (RF) output power for each end device individually, using an Adaptive Data Rate (ADR) scheme. End devices may transmit on any channel allowed by local regulation at any time 🎛️.
LoRaWAN radios use ISM bands, for example, 433 MHz and 868 MHz within the European Union, and 915 MHz in the Americas 🌎.
The end device changes channels in a pseudorandom fashion for every transmission. That helps make the system more robust to interference and/or lets it conform to local regulations 🌀.
Figure 2 shows that after a transmission slot, a Class A device turns on its receiver for two short receive windows that are offset from the end of the transmission window. End devices can only transmit a subsequent uplink frame after the end of the associated receive windows. When a device joins a LoRaWAN network, there are similar timeouts on parts of that process ⏳.
Part 1 of 10 is done, bestie 🧚 more parts are coming, so stay tuned!! 💖
|----------------------------| |--------| |--------|
| Tx | | Rx | | Rx |
|----------------------------| |--------| |--------|
|---------|
Rx delay 1
|------------------------|
Rx delay 2
Figure 2: LoRaWAN Class A Transmission and Reception WindowOkay so the regional rules for the LoRaWAN PHY are a whole thing 😭 The full spec is more than 30 pages, so we're not copying all of it here 💅 Instead, we're showing you the kinds of issues people run into. Table 1 has some default settings for one ISM band (we're not fully explaining them here, sorry bestie 🙈), and Table 2 has the maxima and minima for the parameters you'd care about if you're trying to run IETF protocols over the LoRaWAN MAC layer. 🌸
+-----------------------+-------------------------------------------+
| Parameters | Default Value |
+-----------------------+-------------------------------------------+
| Rx delay 1 | 1 s |
| | |
| Rx delay 2 | 2 s (must be RECEIVE_DELAY1 + 1 s) |
| | |
| join delay 1 | 5 s |
| | |
| join delay 2 | 6 s |
| | |
| 868MHz Default | 3 (868.1,868.2,868.3), data rate: 0.3-50 |
| channels | kbit/s |
+-----------------------+-------------------------------------------+
Table 1: Default Settings for EU 868 MHz Band
+------------------------------------------------+--------+---------+
| Parameter/Notes | Min | Max |
+------------------------------------------------+--------+---------+
| Duty Cycle: some but not all ISM bands impose | 1% | no |
| a limit in terms of how often an end device | | limit |
| can transmit. In some cases, LoRaWAN is more | | |
| restrictive in an attempt to avoid congestion. | | |
| | | |
| EU 868 MHz band data rate/frame size | 250 | 50000 |
| | bits/s | bits/s |
| | : 59 | : 250 |
| | octets | octets |
| | | |
| US 915 MHz band data rate/frame size | 980 | 21900 |
| | bits/s | bits/s |
| | : 19 | : 250 |
| | octets | octets |
+------------------------------------------------+--------+---------+
Table 2: Minima and Maxima for Various LoRaWAN ParametersNote that, for the smallest frame size (19 octets) 🥺, 8 octets go to the LoRa MAC layer headers, which leaves only 11 octets for payload (including MAC layer options). Those settings don't apply to the join procedure though 🙅♀️. End devices are required to use a channel and data rate that can send the 23-byte Join-Request message.
Uplink and downlink higher-layer data rides along in a MACPayload 📦. There's a concept of "ports" (an optional 8-bit value) so one end device can handle different applications ✨. Port zero is reserved for LoRaWAN-specific messaging, like configuring the end device's network parameters (available channels, data rates, ADR parameters, Rx Delay 1 and 2, etc.) 🧚
On top of carrying higher-layer PDUs, there are Join-Request and Join-Response (aka Join-Accept) messages for getting onto the network 🔑. There are also "MAC commands" (more on those below) up to 15 bytes long, which can be piggybacked in an options field ("FOpts") 💜.
There are a bunch of MAC commands for link and device status checking, ADR and duty cycle negotiation, and managing the RX windows and radio channel settings 🎀. For example, the link check response lets the NS (replying to a request from an end device) tell the end device about the signal attenuation it most recently saw at a Gateway, plus how many Gateways received the matching link request MAC command 📡.
Some MAC commands come from the network server itself 👑. One lets the network server ask an end device to cut its duty cycle so it only uses a proportion of the maximum allowed in a region 🫶. Another lets the network server check the end device's power status. The device replies with whether it has an external power source or runs on battery, and if it's on battery, it also sends a relative battery level 🔋.
To work nominally on a LoRaWAN network, a device needs a 32-bit device address 🦋. That address is either assigned when the device "joins" the network (more on the join procedure below) or pre-provisioned into the device. For roaming devices, the device address is based on the 24-bit network identifier (NetID) that the LoRa Alliance allocates to the network. Non-roaming devices can get device addresses from the network without needing a NetID from the LoRa Alliance 🌈.
End devices are assumed to work with one application, or a pretty limited number of them 💅. Applications are identified by a 64-bit AppEUI, which is assumed to be a registered IEEE EUI64 value [EUI64]. A device also needs two symmetric session keys: one protects network artifacts (port=0), the NwkSKey, and the other protects application-layer traffic, the AppSKey. Both keys are used for 128-bit AES cryptographic operations 🔐. So one option is for an end device to already have all of the above, plus channel information, provisioned somehow ahead of time. In that case the end device can just start transmitting 🚀. Given how LoRaWAN networks work, this is often doable through out-of-band means. Table 3 sums these values up.
+---------+---------------------------------------------------------+
| Value | Description |
+---------+---------------------------------------------------------+
| DevAddr | DevAddr (32 bits) = device-specific network address |
| | generated from the NetID |
| | |
| AppEUI | IEEE EUI64 value corresponding to the join server for |
| | an application |
| | |
| NwkSKey | 128-bit network session key used with AES-CMAC |
| | |
| AppSKey | 128-bit application session key used with AES-CTR |
| | |
| AppKey | 128-bit application session key used with AES-ECB |
+---------+---------------------------------------------------------+
Table 3: Values Required for Nominal OperationThe other route is the LoRaWAN join procedure 🤝. Here the end device uses a join server behind the NS to set up some of these values and dynamically get access to the network. To use the join procedure, an end device still needs to know the AppEUI, plus a different long-term symmetric key that's bound to the AppEUI. That's the application key (AppKey), and it's not the same thing as the application session key (AppSKey) 🗝️. The AppKey is required to be specific to the device, so each end device should have its own different AppKey value 💖. Last but not least, the end device needs a long-term identifier for itself. It's syntactically also an EUI-64 and is known as the device EUI or DevEUI 🪪. Table 4 sums these up.
+---------+----------------------------------------------------+
| Value | Description |
+---------+----------------------------------------------------+
| DevEUI | IEEE EUI64 naming the device |
| | |
| AppEUI | IEEE EUI64 naming the application |
| | |
| AppKey | 128-bit long-term application key for use with AES |
+---------+----------------------------------------------------+
Table 4: Values Required for Join ProcedureThe join procedure is a special exchange. The end device sends the AppEUI and DevEUI in a Join-Request uplink message. They're integrity protected with the long-term AppKey, but they're not encrypted 👀. That message gets routed to the network server, which talks to whatever entity knows that AppKey to verify the Join-Request ✅. If everything goes well, the network server sends a Join-Accept downlink message back to the end device. That message specifies the 24-bit NetID, the 32-bit DevAddr, and channel information. The AppSKey and NwkSKey can be derived from it, based on knowing the AppKey 🌟. This gives the end device all the values listed in Table 3 🎉.
All payloads are encrypted and have data integrity 🔒. MAC commands sent as a payload (port zero) are therefore protected. MAC commands piggybacked as frame options ("FOpts") are sent in clear though 😬. Any MAC commands sent as frame options, not just as payload, are visible to a passive attacker. They're not malleable for an active attacker, though, thanks to the Message Integrity Check (MIC) described below 🛡️.
For LoRaWAN version 1.0.x, the NwkSKey session key is used to provide data integrity between the end device and the network server. The AppSKey is used to provide data confidentiality between the end device and network server, or to the application "behind" the network server, depending on the implementation of the network. 🧠
All MAC-layer messages have an outer 32-bit MIC, calculated with AES-CMAC using the ciphertext payload, the other headers, and the NwkSkey as input 🔏. Payloads are encrypted with AES-128, using a counter-mode derived from [IEEE.802.15.4] with the AppSKey 💜. Gateways aren't expected to be given the AppSKey or NwkSKey. All the infrastructure-side cryptography happens in (or "behind") the network server 🏰. When session keys are derived from the AppKey during the join procedure, the Join-Accept message payload is handled in a special way ✨.
The long-term AppKey is used directly to protect the Join-Accept message content. The function isn't an AES-encrypt operation, though. It's an AES-decrypt operation 🙃. The reason is that the end device then only needs to implement AES-encrypt. (The counter-mode variant used for payload decryption means the end device doesn't need an AES-decrypt primitive either 🧚♀️.)
Okay so the Join-Accept plaintext is always less than 16 bytes long, which is why Electronic Code Book (ECB) mode is the one used to protect Join-Accept messages 💅. The Join-Accept message carries an AppNonce (a 24-bit value 🔢). The end device recovers it along with the rest of the Join-Accept content, like DevAddr, using the AES-encrypt operation. Once the end device has the Join-Accept payload, it derives the session keys from the AppKey, AppNonce, and other values. It does that with another ECB mode AES-encrypt operation, where the plaintext input is a maximum of 16 octets. So efficient 🦋
2.2. Narrowband IoT (NB-IoT)
2.2.1. Provenance and Documents
Narrowband Internet of Things (NB-IoT) was developed and standardized by 3GPP 🌈 The standardization was finalized with 3GPP Release 13 in June 2016, and further enhancements for NB-IoT are specified in 3GPP Release 14 in 2017 (for example, in the form of multicast support) ✨ More features and improvements will be developed in the following releases, but NB-IoT has been ready to deploy since 2016. It's rather simple to deploy, especially in the existing LTE networks, which only need a software upgrade in the operator's base stations 🙌
If you want the details, 3GPP specification 36.300 [TGPP36300] gives an overview and overall description of the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) radio interface protocol architecture 📚 Then specifications 36.321 [TGPP36321], 36.322 [TGPP36322], 36.323 [TGPP36323], and 36.331 [TGPP36331] get into the nitty-gritty of the MAC, Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Radio Resource Control (RRC) protocol layers, respectively 🤓 Heads up that the description below assumes you're already familiar with numerous 3GPP terms 💀
For a general overview of NB-IoT, see [nbiot-ov] 💜
2.2.2. Characteristics ✨
okay bestie, let's talk NB-IoT specs 🦋 the targets are lowkey iconic: module cost of less than US $5, extended coverage of 164 dB maximum coupling loss, battery life of over 10 years, ~55000 devices per cell, and uplink reporting latency of less than 10 seconds. 💖
NB-IoT runs Half Duplex Frequency Division Duplex (FDD) 🌸 with peak rates of 60 kbit/s in uplink and 30 kbit/s in downlink. The Maximum Transmission Unit (MTU) is 1600 bytes, and that limit comes from the PDCP layer (check Figure 4 for the protocol structure). PDCP is the highest layer in the user plane, and we'll get into that later 🧚. Higher layers can hand the NB-IoT stack any packet up to that MTU size. The RLC layer then does the segmenting, and it can chop data into transmission blocks as small as 16 bits. The "narrow" in the name is real: NB-IoT uses narrowbands that are 180 kHz wide in both downlink and uplink. ✨
For the air interface, downlink uses Orthogonal Frequency-Division Multiplex (OFDMA) with 15 kHz sub-carrier spacing. Uplink uses Sub-Carrier Frequency-Division Multiplex (SC-FDMA) single tone with either 15kHz or 3.75 kHz tone spacing. Optionally, multi-tone SC-FDMA can be used with 15 kHz tone spacing. It's giving precision 💅
NB-IoT can be deployed in three ways 👑. In-band means the narrowband sits inside an LTE band, and radio resources are flexibly shared between NB-IoT and the normal LTE carrier. Guard-band means the narrowband uses the unused resource blocks between two adjacent LTE carriers. Standalone means the narrowband lives alone in dedicated spectrum, which makes it possible, for example, to reframe a GSM carrier at 850/900 MHz for NB-IoT. All three modes are used in licensed frequency bands. The maximum transmission power is either 20 or 23 dBm for uplink transmissions. For downlink, the eNodeB may use higher transmission power, up to 46 dBm depending on the deployment. 🔥
The Maximum Coupling Loss (MCL) target for NB-IoT coverage enhancements, as defined by 3GPP, is 164 dB. With that MCL, downlink performance lands somewhere between 200 bps and 2-3 kbit/s, depending on the deployment mode. Standalone operation gets the highest data rates, up to a few kbit/s, while in-band and guard-band operation can reach several hundreds of bps. NB-IoT may even operate with an MCL higher than 170 dB, but then the bit rates are very low 🙈
For signaling optimization, there are two options on top of the legacy LTE RRC connection setup. The first is mandatory Data-over-NAS (Control Plane optimization, solution 2 in [TGPP23720]). The second is optional RRC Suspend/Resume (User Plane optimization, solution 18 in [TGPP23720]). 🎀
In the control-plane optimization, data goes over the Non-Access Stratum (NAS), directly to and from the Mobile Management Entity (MME) (see Figure 3 for the network architecture) in the core network, and reaches the User Equipment (UE) without involving the base station. The catch is that there's no Access Stratum security or header compression from the PDCP layer in the eNodeB, since the Access Stratum gets bypassed. Only limited RRC procedures are available. Header compression based on Robust Header Compression (RoHC) may still optionally be provided, and it gets terminated in the MME. 🫶
The RRC Suspend/Resume procedures cut down the signaling overhead needed for a UE to move from RRC Idle to RRC Connected mode, compared to legacy LTE. The result is a quicker user-plane transaction with the network and a faster return to RRC Idle mode 🚀
To help device battery life, both Power-Saving Mode (PSM) and extended DRX (eDRX) are available to NB-IoT. With eDRX, the RRC Connected mode DRX cycle can be up to 10.24 seconds. In RRC Idle, the eDRX cycle can be up to 3 hours. In PSM, the device sits in a deep sleep state and only wakes up to do uplink reporting. After reporting, there's a window (configured by the network) during which the device receiver is open for downlink connectivity or periodic "keep-alive" signaling. PSM uses periodic TAU signaling, with additional reception windows for downlink reachability. 😭
Since NB-IoT operates in licensed spectrum, it has no channel access restrictions, so it can go up to a 100% duty cycle. 💜
3GPP access security is specified in [TGPP33203]. 🔐
+--+
|UE| \ +------+ +------+
+--+ \ | MME |------| HSS |
\ / +------+ +------+
+--+ \+--------+ / |
|UE| ----| eNodeB |- |
+--+ /+--------+ \ |
/ \ +--------+
/ \| | +------+ Service Packet
+--+ / | S-GW |----| P-GW |---- Data Network (PDN)
|UE| | | +------+ e.g., Internet
+--+ +--------+
Figure 3: 3GPP Network ArchitectureFigure 3 shows the 3GPP network architecture, which applies to NB-IoT. The MME handles mobility for the UE. Its jobs include tracking and paging UEs, session management, choosing the Serving Gateway for the UE during initial attachment, and authenticating the user. The NAS signaling from the UE terminates at the MME. 🧠
The Serving Gateway (S-GW) routes and forwards user data packets through the access network. It also acts as a mobility anchor for UEs during handover between base stations (known as eNodeBs), and during handovers between NB-IoT and other 3GPP technologies. 🌈
The Packet Data Network Gateway (P-GW) works as the interface between the 3GPP network and external networks. 🍓
The Home Subscriber Server (HSS) holds user-related and subscription-related information. It's a database that handles mobility management, session-establishment support, user authentication, and access authorization. 👑
E-UTRAN is made up of components of a single type, the eNodeB. An eNodeB is a base station that controls the UEs in one or several cells. 🏠
The 3GPP radio protocol architecture is shown in Figure 4.
+---------+ +---------+
| NAS |----|-----------------------------|----| NAS |
+---------+ | +---------+---------+ | +---------+
| RRC |----|----| RRC | S1-AP |----|----| S1-AP |
+---------+ | +---------+---------+ | +---------+
| PDCP |----|----| PDCP | SCTP |----|----| SCTP |
+---------+ | +---------+---------+ | +---------+
| RLC |----|----| RLC | IP |----|----| IP |
+---------+ | +---------+---------+ | +---------+
| MAC |----|----| MAC | L2 |----|----| L2 |
+---------+ | +---------+---------+ | +---------+
| PHY |----|----| PHY | PHY |----|----| PHY |
+---------+ +---------+---------+ +---------+
LTE-Uu S1-MME
UE eNodeB MME
Figure 4: 3GPP Radio Protocol Architecture for the Control PlaneThe radio protocol architecture of NB-IoT (and LTE) is split into the control plane and the user plane. The control plane has protocols that control the radio-access bearers and the connection between the UE and the network. The highest layer of the control plane is the Non-Access Stratum (NAS). It carries radio signaling between the UE and the Evolved Packet Core (EPC), passing transparently through the radio network. The NAS handles authentication, security control, mobility management, and bearer management. 🧁
The Access Stratum (AS) is the functional layer below the NAS. In the control plane, it consists of the Radio Resource Control (RRC) protocol [TGPP36331]. RRC handles connection establishment and release, broadcast of system information, and radio-bearer establishment, reconfiguration, and release. It configures the user and control planes according to the network status. There are two RRC states, RRC_Idle and RRC_Connected, and the RRC entity controls switching between them. ✨
In RRC_Idle, the network knows the UE is present, and the UE can be reached in case of an incoming call or downlink data. In this state, the UE monitors paging, performs cell measurements and cell selection, and acquires system information. The UE can also receive broadcast and multicast data, but it is not expected to transmit or receive unicast data. In RRC_Connected, the UE has a connection to the eNodeB, the network knows the UE location at the cell level, and the UE may receive and transmit unicast data. An RRC connection is established when the UE is expected to be active in the network, to transmit or receive data. The RRC connection is released, switching back to RRC_Idle, when there's no more traffic. This is to preserve UE battery life and radio resources. 🔋
However, as mentioned earlier, NB-IoT introduces a new feature that lets data go from the MME directly to the UE, and then transparently to the eNodeB, bypassing AS functions. 🦄
The PDCP's [TGPP36323] main services in the control plane are transfer of control-plane data, ciphering, and integrity protection. 🔒
The RLC protocol [TGPP36322] transfers upper-layer PDUs and, optionally, does error correction with Automatic Repeat reQuest (ARQ). It also handles concatenation, segmentation, and reassembly of RLC Service Data Units (SDUs), in-sequence delivery of upper-layer PDUs, duplicate detection, RLC SDU discarding, RLC re-establishment, and protocol error detection and recovery. 🧩
The MAC protocol [TGPP36321] maps logical channels to transport channels, multiplexes MAC SDUs, reports scheduling information, does error correction with Hybrid ARQ (HARQ), handles priority, and selects the transport format. 🎯
The PHY [TGPP36201] provides data-transport services to higher layers. These include error detection and indication to higher layers, Forward Error Correction (FEC) encoding, HARQ soft-combining, rate-matching, mapping of transport channels onto physical channels, power-weighting and modulation of physical channels, frequency and time synchronization, and radio characteristics measurements. 📡
The user plane transfers user data through the Access Stratum. It interfaces with IP, and its highest layer is the PDCP. In the user plane, the PDCP does header compression using RoHC, transfers user-plane data between the eNodeB and the UE, and handles ciphering and integrity protection. Like the control plane, the lower layers in the user plane (RLC, MAC, and the PHY) do the same jobs they do in the control plane. 💜
2.3. Sigfox
2.3.1. Provenance and Documents 🌍
The Sigfox LPWAN follows the terminology and specifications defined by ETSI [etsi_unb]. As of today, Sigfox's network is fully deployed in 12 countries, with ongoing deployments in 26 other countries. That adds up to a total geography of 2 million square kilometers, home to 512 million people. 🌸
2.3.2. Characteristics ✨
Okay so Sigfox LPWAN devices are autonomous and battery-operated, and they only send a few bytes per day, week, or month 🔋. In principle, that means one battery can last them up to 10-15 years 💖. The system is built so devices can last several years, sometimes even buried underground 🌱.
Since the radio protocol is connectionless and optimized for uplink 📡, a Sigfox base station's capacity depends on how many messages devices generate, not on how many devices are connected 🙌. Same deal for battery life: it depends on how many messages each device sends. Depending on the use case, a device might send less than one message a day or dozens of messages a day 💅.
The coverage of a cell depends on the link budget and the type of deployment (urban, rural, etc.) 🏙️🌾. The radio interface is compliant with these regulations:
- Spectrum allocation in the USA [fcc_ref]
- Spectrum allocation in Europe [etsi_ref1] [etsi_ref2]
- Spectrum allocation in Japan [arib_ref]
The Sigfox radio interface is also compliant with the local regulations of these countries: Australia, Brazil, Canada, Kenya, Lebanon, Mauritius, Mexico, New Zealand, Oman, Peru, Singapore, South Africa, South Korea, and Thailand 🌍✨.
The radio interface is based on Ultra Narrow Band (UNB) communications 🎯. UNB gives you a longer transmission range while spending only a limited amount of energy at the device, which is so smart 🧠. It also lets a large number of devices coexist in one cell without really bumping up the spectrum interference 🫶.
Both uplink and downlink are supported, although the system is optimized for uplink 💜. Because of spectrum optimizations, the uplink and downlink use different frames and different time synchronization methods 🔄.
The main radio characteristics of the UNB uplink transmission are:
- Channelization mask:
100 Hz / 600 Hz(depending on the region) - Uplink baud rate:
100 baud / 600 baud(depending on the region) - Modulation scheme:
DBPSK - Uplink transmission power: compliant with local regulation
- Link budget:
155 dB(or better) - Central frequency accuracy: not relevant, provided there is no significant frequency drift within an uplink packet transmission
For example, in Europe the UNB uplink frequency band is limited to 868.00 to 868.60 MHz, with a maximum output power of 25 mW and a duty cycle of 1% 🇪🇺.
The format of the uplink frame looks like this 👀:
+--------+--------+--------+------------------+-------------+-----+
|Preamble| Frame | Dev ID | Payload |Msg Auth Code| FCS |
| | Sync | | | | |
+--------+--------+--------+------------------+-------------+-----+Figure 5: Uplink Frame Format 🎀
The uplink frame is made up of these fields:
- Preamble:
19 bits - Frame sync and header:
29 bits - Device ID:
32 bits - Payload:
0-96 bits - Authentication:
16-40 bits - Frame check sequence:
16 bits(Cyclic Redundancy Check (CRC))
The main radio characteristics of the UNB downlink transmission are:
- Channelization mask:
1.5 kHz - Downlink baud rate:
600 baud - Modulation scheme:
GFSK - Downlink transmission power:
500 mW / 4W(depending on the region) - Link budget:
153 dB(or better) - Central frequency accuracy: the center frequency of downlink transmission is set by the network according to the corresponding uplink transmission.
For example, in Europe the UNB downlink frequency band is limited to 869.40 to 869.65 MHz, with a maximum output power of 500 mW with a 10% duty cycle 🌷.
The format of the downlink frame is the following 🦋:
+------------+-----+---------+------------------+-------------+-----+
| Preamble |Frame| ECC | Payload |Msg Auth Code| FCS |
| |Sync | | | | |
+------------+-----+---------+------------------+-------------+-----+Figure 6: Downlink Frame Format 🌸
The downlink frame is made up of these fields:
- Preamble:
91 bits - Frame sync and header:
13 bits - Error Correcting Code (ECC):
32 bits - Payload:
0-64 bits - Authentication:
16 bits - Frame check sequence:
8 bits(CRC)
The radio interface is optimized for uplink transmissions, which are asynchronous ⏱️. Downlink communication happens when devices ask the network whether any data is waiting for them 🙋♀️.
A device that wants to receive downlink messages opens a fixed reception window right after it sends an uplink transmission 🪟. The delay and duration of that window have fixed values. The network sends a device's downlink message during that reception window, and the network also picks the BS that will transmit it 👑.
Uplink and downlink traffic is unbalanced because of the regulatory constraints on ISM bands 📉. Under the strictest regulations, the system can allow a maximum of 140 uplink messages and 4 downlink messages per device per day 💀. These restrictions can be slightly relaxed depending on system conditions and the specific regulatory domain of operation 🧚.
Here's the Sigfox network architecture 🗺️:
+---+
|DEV| * +------+
+---+ * | RA |
* +------+
+---+ * |
|DEV| * * * * |
+---+ * +----+ |
* | BS | \ +--------+
+---+ * +----+ \ | |
DA -----|DEV| * * * | SC |----- NA
+---+ * / | |
* +----+ / +--------+
+---+ * | BS |/
|DEV| * * * * +----+
+---+ *
*
+---+ *
|DEV| * *
+---+Figure 7: Sigfox Network Architecture
Figure 7 depicts the different elements of the Sigfox network architecture 🔍.
Sigfox has a "one-contract one-network" model, which lets devices connect in any country without any need for, or notion of, roaming or handover 🌎💫.
The architecture is one single cloud-based core network ☁️. That gives you global connectivity with minimal impact on the end device and the radio access network 🥰. The core network elements are the Service Center (SC) and the Registration Authority (RA). The SC handles data connectivity between the BS and the Internet, plus the control and management of the BSs and End Points (EPs) 🧠. The RA is in charge of EP network access authorization 🔐.
The radio access network is made up of several BSs connected directly to the SC 📶. Each BS performs complex L1/L2 functions and leaves some L2 and L3 functionalities to the SC 🤓.
Devices (DEVs) or EPs are the objects that communicate application data between local Device Applications (DAs) and Network Applications (NAs) 💌.
Devices (or EPs) can be static or nomadic 🚶♀️. They associate with the SC and do not attach to any specific BS, so they can communicate with the SC through one or multiple BSs 🌐.
Because devices have limited complexity, it is assumed that they host only one or very few device applications 🧩. Most of the time, each of those applications communicates with a single network application at a time 💜.
The radio protocol authenticates and ensures the integrity of each message 🛡️. It does this with a unique device ID and an AES-128-based message authentication code, which makes sure the message was generated and sent by the device with the ID claimed in the message 🔑. Application data can be encrypted at the application level or not, depending on how critical the use case is, to balance cost and effort against risk ⚖️. AES-128 in counter mode is used for encryption 🎀. Cryptographic keys are independent for each device 🗝️. These keys are associated with the device ID, and separate integrity and confidentiality keys are pre-provisioned. A confidentiality key is only provisioned if confidentiality is going to be used 🙈. At the time of writing, the algorithms and keying details for this are not published 🤫.
2.4. Wi-SUN Alliance Field Area Network (FAN) 🌈
Text here is via personal communication from Bob Heile (bheile@ieee.org) and was authored by Bob and Sum Chin Sean 💌. Paul Duffy (paduffy@cisco.com) also provided additional comments and input on this section 🫶.
2.4.1. Provenance and Documents 📚
The Wi-SUN Alliance (<https://www.wi-sun.org/>) is an industry alliance for smart city, smart grid, smart utility, and a broad set of general IoT applications 🏙️⚡. The Wi-SUN Alliance Field Area Network (FAN) profile is open-standards based (primarily on IETF and IEEE 802 standards) 🔓. It was developed to address applications like smart municipality and city infrastructure monitoring and management, Electric Vehicle (EV) infrastructure, Advanced Metering Infrastructure (AMI), Distribution Automation (DA), Supervisory Control and Data Acquisition (SCADA) protection and management, distributed generation monitoring and management, and many more IoT applications 🚀. The Alliance has also created a certification program to promote global multi-vendor interoperability 🏆.
The FAN profile is specified within ANSI/TIA as an extension of work previously done on Smart Utility Networks [ANSI-4957-000] 🛠️. Updates to those specifications, intended to be published in 2017, will contain details of the FAN profile 🗓️. A current snapshot of the work to produce that profile is presented in [wisun-pressie1] and [wisun-pressie2] 📽️✨.
2.4.2. Characteristics ✨
okay bestie, let's get into the Wi-SUN FAN vibes 💅🦋 this profile is an IPv6 wireless mesh network with support for enterprise-level security, and it is giving robust, reliable, and very scalable 😭🫶 the frequency-hopping mesh is built for superior network robustness, reliability thanks to high redundancy, good scalability thanks to its flexible mesh configuration, and good resilience to interference 🔥. very low power modes are still in development so network nodes can run on battery for the long haul 🔋💜
here are some overall Wi-SUN characteristics that matter for LPWAN apps, periodt 🎀
Coverage: FAN range is typically 2 - 3 km in line of sight, which is perfect for neighborhood area networks, campus area networks, or corporate area networks 🏘️🌸 you can extend the range with multi-hop networking too ✨
High-bandwidth, low-link latency: Wi-SUN supports relatively high bandwidth, up to 300 kbit/s [FANOV] 📈 it lets devices get remote updates and upgrades so they can handle new applications and keep their working life going 🧚 it also supports LPWAN IoT apps that need on-demand control, with low link latency (0.02 s) and bidirectional communication 💖
Low-power consumption: FAN devices draw less than 2 uA when resting and only 8 mA when listening 🌙 so they can keep a long lifetime even when they're listening a lot 🙈 for example, say the device transmits data for 10 ms once every 10 s; theoretically, a 1000 mAh battery can last more than 10 years 😭🔋✨
Scalability: tens of millions of Wi-SUN FAN devices have been deployed in urban, suburban, and rural environments, including deployments with more than 1 million devices 🌈👑
A FAN contains one or more networks, and within a network, nodes take on one of three operational roles 🦋 first up is the Border Router, which provides WAN connectivity to the network 🌐 it maintains source-routing tables for all nodes in its network, provides node authentication and key management services, and disseminates network-wide information such as broadcast schedules 📋 second are the Router nodes, which handle upward and downward packet forwarding within a network 🔁 a Router also provides services for relaying security and address management protocols 🔐 last but not least, Leaf nodes provide minimum capabilities, like discovering and joining a network and sending/receiving IPv6 packets 🍓 and a low-power network may have a mesh topology with Routers at the edges that construct a star topology with Leaf nodes ⭐
the FAN profile is based on various open IETF standards, including [RFC768], [RFC2460], [RFC4443], and [RFC6282] 📚 related IEEE 802 standards include [IEEE.802.15.4] and [IEEE.802.15.9] 🧠 for Low-Power and Lossy Networks (LLNs), see ANSI/ TIA [ANSI-4957-210] 💜
the FAN profile spec gives you an application-independent IPv6-based transport service 🎀 there are two possible ways to set up IPv6 packet routing: RPL at the Network layer is mandatory, and Multi-Hop Delivery Service (MHDS) at the Data Link layer is optional 🦋 Figure 8 shows the FAN network stack overview 👇
The Transport service is based on UDP (defined in [RFC768]) or TCP (defined in [RFC793]. 🚀
The Network service is provided by IPv6 as defined in [RFC2460], with an IPv6 over Low-Power Wireless Personal Area Networks (6LoWPAN) adaptation as defined in [RFC4944] and [RFC6282]. ICMPv6, as defined in [RFC4443], handles the control plane during information exchange 🌸
The Data Link service handles control and management of the PHY, plus data transfer and management services for the Network layer 💅 those services are split into MAC and Logical Link Control (LLC) sub-layers ✨ the LLC sub-layer provides a protocol dispatch service that supports 6LoWPAN, plus an optional MAC sub-layer mesh service 🫶 the MAC sub-layer is built using data structures defined in [IEEE.802.15.4] 🔧 multiple frequency hopping modes are defined 🔁 the entire MAC payload gets encapsulated in an [IEEE.802.15.9] Information Element, so LLC protocol dispatch can happen between upper-layer 6LoWPAN processing and MAC sub-layer mesh processing, etc. 🧚 these areas will be expanded once [IEEE.802.15.12] is completed 👀
The PHY service is derived from a subset of the SUN FSK specification in [IEEE.802.15.4] 💖 the 2-FSK modulation schemes, with a channel spacing range from 200 to 600 kHz, are defined to provide data rates from 50 to 300 kbit/s, with FEC as an optional feature 📶 towards ultra-low-power apps, the PHY layer design is also extendable to low-energy and critical infrastructure-monitoring networks 🌙
Here's the stack, bestie 👇
+----------------------+--------------------------------------------+
| Layer | Description |
+----------------------+--------------------------------------------+
| IPv6 protocol suite | TCP/UDP |
| | |
| | 6LoWPAN Adaptation + Header Compression |
| | |
| | DHCPv6 for IP address management |
| | |
| | Routing using RPL |
| | |
| | ICMPv6 |
| | |
| | Unicast and Multicast forwarding |
+----------------------+--------------------------------------------+
| MAC based on | Frequency hopping |
| [IEEE.802.15.4e] + | |
| IE extensions | Discovery and Join |
| | |
| | Protocol Dispatch ([IEEE.802.15.9]) |
| | |
| | Several Frame Exchange patterns |
| | |
| | Optional Mesh Under routing |
| | ([ANSI-4957-210]) |
+----------------------+--------------------------------------------+
| PHY based on | Various data rates and regions |
| [IEEE.802.15.4g] | |
+----------------------+--------------------------------------------+
| Security | [IEEE.802.1x]/EAP-TLS/PKI Authentication |
| | TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 |
| | required for EAP-TLS |
| | |
| | 802.11i Group Key Management |
| | |
| | Frame security is implemented as AES-CCM* |
| | as specified in [IEEE.802.15.4] |
| | |
| | Optional [ETSI-TS-102-887-2] Node 2 Node |
| | Key Management |
+----------------------+--------------------------------------------+Figure 8: Wi-SUN Stack Overview 🎀
The FAN security supports Data Link layer network access control, mutual authentication, and a secure pairwise link between a FAN node and its Border Router 🔐 it's implemented with an adaptation of [IEEE.802.1x] and EAP-TLS as described in [RFC5216], using secure device identity as described in [IEEE.802.1AR] 🪪 certificate formats are based on [RFC5280] 📜 a secure group link between a Border Router and a set of FAN nodes is established using an adaptation of the [IEEE.802.11] Four-Way Handshake 🤝 a set of four group keys is maintained within the network, one of which is the current transmit key 🗝️ secure node-to-node links are supported between one-hop FAN neighbors using an adaptation of [ETSI-TS-102-887-2] 💜 and FAN nodes implement Frame Security as specified in [IEEE.802.15.4] 🛡️✨
3. Generic Terminology 💖
okay so LPWAN techs like the ones we just went through have pretty similar architectures, but they all have totally different names for the same stuff 😭 we can spot a few types of entities in a typical LPWAN network:
- End devices are the devices, or the "things" (sensors, actuators, etc.) 🌸 They're named differently in each technology (End Device, User Equipment, or EP), and there can be a high density of end devices per Radio Gateway 🦋
- The Radio Gateway is the EP of the constrained link. It goes by Gateway, Evolved Node B, or base station 📡
- The Network Gateway or Router is the interconnection node between the Radio Gateway and the Internet. It's known as the Network Server, Serving GW, or Service Center 🌈
- The LPWAN-AAA server controls user authentication. It's known as the Join-Server, Home Subscriber Server, or Registration Authority. (We use the term LPWAN-AAA server because we're not assuming that this entity speaks RADIUS or Diameter as many/most AAA servers do; but, equally, we don't want to rule that out, as the functionality will be similar.) 🔐
- Last but not least, the Application Server, also known as Packet Data Node Gateway or Network Application 👑
+---------------------------------------------------------------------+
| Function/ | | | | | |
|Technology | LoRaWAN | NB-IoT | Sigfox | Wi-SUN | IETF |
+-----------+-----------+-----------+------------+--------+-----------+
|Sensor, | | | | | |
|Actuator, | End | User | End | Leaf | Device |
|device, | Device | Equipment | Point | Node | (DEV) |
|object | | | | | |
+-----------+-----------+-----------+------------+--------+-----------+
|Transceiver| | Evolved | Base | Router | Radio |
|Antenna | Gateway | Node B | Station | Node | Gateway |
+-----------+-----------+-----------+------------+--------+-----------+
|Server | Network | PDN GW/ | Service | Border | Network |
| | Server | SCEF* | Center | Router | Gateway |
| | | | | | (NGW) |
+-----------+-----------+-----------+------------+--------+-----------+
|Security | Join | Home |Registration|Authent.| LPWAN- |
|Server | Server | Subscriber| Authority | Server | AAA |
| | | Server | | | Server |
+-----------+-----------+-----------+------------+--------+-----------+
|Application|Application|Application| Network |Appli- |Application|
| | Server | Server | Application| cation | (App) |
+---------------------------------------------------------------------+
* SCEF = Service Capability Exposure Function
Figure 9: LPWAN Architecture Terminology +------+
() () () | |LPWAN-|
() () () () / \ +---------+ | AAA |
() () () () () () / \========| /\ |====|Server| +-----------+
() () () | | <--|--> | +------+ |APPLICATION|
() () () () / \============| v |==============| (App) |
() () () / \ +---------+ +-----------+
DEV Radio Gateways NGW
Figure 10: LPWAN ArchitectureIn addition to the names of entities, LPWANs are also subject to possibly regional frequency-band regulations 🌍 Those may include restrictions on the duty cycle, for example, requiring that hosts only transmit for a certain percentage of each hour ⏰
4. Gap Analysis 🔍
This section looks at some of the gaps between current LPWAN technologies and the goals of the LPWAN WG 👀 Many of the generic considerations described in [RFC7452] will also apply in LPWANs, since end devices can also be considered to be a subclass of (so-called) "smart objects" 🧸 On top of that, LPWAN device implementers will also need to consider the issues relating to firmware updates described in [RFC8240] 🔄
4.1. Naive Application of IPv6 🙈
IPv6 [RFC8200] was designed to allocate addresses to all the nodes connected to the Internet, and honestly that's iconic ✨ But the header overhead of at least 40 bytes it brings along is totally incompatible with LPWAN constraints 💀 If IPv6 with no further optimization were used, several LPWAN frames could be needed just to carry the IP header 📦 Another problem comes from IPv6 MTU requirements, which require the layer below to support at least 1280 byte packets [RFC2460] 😤
IPv6 has a configuration protocol: Neighbor Discovery Protocol (NDP) [RFC4861]). For a node to learn network parameters, NDP generates regular traffic with a relatively large message size that does not fit LPWAN constraints 🫠
In some LPWAN technologies, L2 multicast is not supported. In that case, if the network topology is a star, the solution and considerations from Section 3.2.5 of [RFC7668] may be applied 🌟
Other key protocols (such as DHCPv6 [RFC3315], IPsec [RFC4301] and TLS [RFC5246]) have similarly problematic properties in this context 🥲 Each protocol requires relatively frequent round-trips between the host and some other host on the network. For cryptographic protocols (such as IPsec and TLS), the round-trips needed for secure session establishment are only part of it. Cryptographic operations can also require padding and the addition of authenticators, which are problematic when you're considering LPWAN lower layers 🔐 Note that mains powered Wi-SUN mesh router nodes will typically be more resource capable than the other LPWAN technologies discussed 🔌 This can enable use of more "chatty" protocols for some aspects of Wi-SUN 💬
4.2. 6LoWPAN 🦋
Several technologies that have significant constraints in various dimensions have exploited the 6LoWPAN suite of specifications ([RFC4944], [RFC6282], and [RFC6775]) to support IPv6 [USES-6LO] 🧚 However, LPWAN constraints are often more extreme than those typical of technologies that have (re-)used 6LoWPAN, so they're a real challenge for the 6LoWPAN suite when it comes to enabling IPv6 over LPWAN 😩 LPWANs are characterized by device constraints (in terms of processing capacity, memory, and energy availability), and especially by link constraints, such as:
- tiny L2 payload size (from ~10 to ~100 bytes),
- very low bit rate (from ~10 bit/s to ~100 kbit/s), and
- in some specific technologies, further message rate constraints (e.g., between ~0.1 message/minute and ~1 message/minute) due to regional regulations that limit the duty cycle 📉
4.2.1. Header Compression 🗜️
6LoWPAN header compression reduces IPv6 (and UDP) header overhead by eliding header fields when they can be derived from the link layer, and by assuming that some of the header fields will frequently carry expected values 🎀 6LoWPAN provides both stateless and stateful header compression. In the latter, all nodes of a 6LoWPAN are assumed to share compression context. In the best case, the IPv6 header for link-local communication can be reduced to only 2 bytes ✨ For global communication, the IPv6 header may be compressed down to 3 bytes in the most extreme case. However, in more practical situations, the smallest IPv6 header size may be 11 bytes (one address prefix compressed) or 19 bytes (both source and destination prefixes compressed). These headers are large considering the link-layer payload size of LPWAN technologies, and in some cases, they're even bigger than the LPWAN PDUs 😭 6LoWPAN was initially designed for [IEEE.802.15.4] networks with a frame size up to 127 bytes and a throughput of up to 250 kbit/s, which may or may not be duty cycled 🫶
4.2.2. Address Autoconfiguration 🏷️
Traditionally, Interface Identifiers (IIDs) have been derived from link-layer identifiers [RFC4944]. This allows optimizations such as header compression 💜 Nevertheless, recent guidance has advised that, due to privacy concerns, 6LoWPAN devices should not be configured to embed their link-layer addresses in the IID by default 🙈 [RFC8065] provides guidance on better methods for generating IIDs 🔒
4.2.3. Fragmentation 🧩
As stated above, IPv6 requires the layer below to support an MTU of 1280 bytes [RFC8200]. Therefore, given the low maximum payload size of LPWAN technologies, fragmentation is needed 🧩
If a layer of an LPWAN technology supports fragmentation, proper analysis has to be carried out to decide whether the fragmentation functionality provided by the lower layer or fragmentation at the adaptation layer should be used. Otherwise, fragmentation functionality shall be used at the adaptation layer 🧠
6LoWPAN defined a fragmentation mechanism and a fragmentation header to support the transmission of IPv6 packets over IEEE.802.15.4 networks [RFC4944]. While the 6LoWPAN fragmentation header is appropriate for the 2003 version of [IEEE.802.15.4] (which has a frame payload size of 81-102 bytes), it is not suitable for several LPWAN technologies, many of which have a maximum payload size that is one order of magnitude below that of the 2003 version of [IEEE.802.15.4] 📉 The overhead of the 6LoWPAN fragmentation header is high, considering the reduced payload size of LPWAN technologies and the limited energy availability of the devices using them 🔋 Furthermore, its datagram offset field is expressed in increments of eight octets. In some LPWAN technologies, the 6LoWPAN fragmentation header plus eight octets from the original datagram exceed the available space in the layer two payload 😵 In addition, the MTU in LPWAN networks could be variable, which implies a variable fragmentation solution 🌀
4.2.4. Neighbor Discovery 🗺️
6LoWPAN Neighbor Discovery [RFC6775] defines optimizations to IPv6 ND [RFC4861], in order to adapt its functionality for networks of devices using [IEEE.802.15.4] or similar technologies 🔧 The optimizations comprise host-initiated interactions to allow for sleeping hosts, replacement of multicast-based address resolution for hosts by an address registration mechanism, multihop extensions for prefix distribution and duplicate address detection (note that these are not needed in a star topology network), and support for 6LoWPAN header compression 🌸
6LoWPAN ND may be used in not so severely constrained LPWAN networks 🌤️ The relative overhead incurred will depend on the LPWAN technology used (and on its configuration, if appropriate). In certain LPWAN setups (with a maximum payload size above ~60 bytes and duty-cycle-free or equivalent operation), an RS/RA/NS/NA exchange may be completed in a few seconds, without incurring packet fragmentation ⚡
In other LPWANs (with a maximum payload size of ~10 bytes and a message rate of ~0.1 message/minute), the same exchange may take hours or even days, leading to severe fragmentation and consuming a significant amount of the available network resources 🥴 6LoWPAN ND behavior may be tuned through the use of appropriate values for the default Router Lifetime, the Valid Lifetime in the PIOs, and the Valid Lifetime in the 6LoWPAN Context Option (6CO), as well as the address Registration Lifetime ⏳ However, for the latter LPWANs mentioned above, 6LoWPAN ND is not suitable 🚫
4.3. 6lo 🧚
Okay so the 6lo WG has been reusing and adapting 6LoWPAN 💖 to get IPv6 running over link-layer tech like Bluetooth Low Energy (BTLE), ITU-T G.9959 [G9959], Digital Enhanced Cordless Telecommunications (DECT) Ultra Low Energy (ULE), MS/TP-RS485, Near Field Communication (NFC) IEEE 802.11ah. (You can check out https://datatracker.ietf.org/wg/6lo/ for the deets on the 6lo WG 🫶.) These techs are kinda similar in a bunch of ways to [IEEE.802.15.4], which was the OG 6LoWPAN target tech ✨.
6lo has mostly used the subset of 6LoWPAN techniques that fit each lower-layer tech best 🎀. It also added extra optimizations for techs that use a star topology, like BTLE or DECT-ULE 🌸.
The main constraint in these networks comes from the devices themselves (constrained devices) 🥺. In LPWANs, though, it's the network itself that's the most stressful constraint 💀.
4.4. 6tisch 🦋
The IPv6 over the TSCH mode of IEEE 802.15.4e (6tisch) solution is built for mesh networks that run on the [IEEE.802.15.4e] MAC with a deterministic slotted channel 🍓. Time-Slotted Channel Hopping (TSCH) can help cut down on collisions and balance things better across the channels 🌈. It also saves battery life by not wasting time on idle listening for the return channel 🔋✨.
A big key to 6tisch is using synchronization to get that determinism 👑. TSCH and 6tisch may come with a standard scheduling function 💅. The LPWAN networks probably won't support synchronization like the one 6tisch uses 😭.
4.5. RoHC 💜
RoHC is a header compression mechanism [RFC3095] built for multimedia flows on a point-to-point channel 📞. It uses three levels of compression, and each level has its own header format 🔥. At the first level, RoHC sends 52 bytes of header 😵. At the second level, the header could be anywhere from 34 to 15 bytes 🙈. At the third level, the header size could be from 7 to 2 bytes ⭐.
The compression level is managed by a Sequence Number (SN), which goes from 2 bytes all the way down to 4 bits under minimal compression 🧠. SN compression is done with an algorithm called Window-Least Significant Bits (W-LSB) 🪄. This window is 4 bits big and represents 15 packets, so every 15 packets RoHC has to slide the window to get the right SN 🌀. And sliding the window means the compression level goes down 📉. When packets get lost or errored, the decompressor loses its context and drops packets until a bigger header shows up with more complete info 💔. To estimate RoHC's performance, people use an average header size 📊. That average depends on the transmission conditions, but most of the time it lands between 3 and 4 bytes 🍬.
RoHC hasn't been adapted specifically for the constrained hosts and networks of LPWANs 🥲. It doesn't account for energy limits or the transmission rate 🔋. On top of that, the RoHC context gets synchronized during transmission, which doesn't allow for better compression 🙃.
4.6. ROLL 🌷
Most technologies the LPWAN WG looked at are built on a star topology, which means there's no need for routing at that layer 🌟. Future work might cover more use cases that could need existing routing protocols to be adapted, or new ones defined 💫. As of writing, work like what's done in the Routing Over Low-Power and Lossy Network (ROLL) WG, plus other routing protocols, is out of scope for the LPWAN WG 🚫.
4.7. CoAP 🌸
The Constrained Application Protocol (CoAP) [RFC7252] gives you a RESTful framework for apps meant to run on constrained IP networks 🎀. It might be necessary to adapt CoAP or related protocols to handle the extreme duty cycles and the potentially super limited throughput of LPWANs 🥀.
For example, some of CoAP's timers may need to be redefined ⏰. Taking CoAP acknowledgments into account may let you reduce the L2 acknowledgments 🤝. On the other hand, there's current work in progress in the CoRE WG on the Constrained Management Interface (COMI) / Constrained Objects Language (CoOL) network management interface 🛠️. It uses Structured Identifiers (SIDs) to shrink payload size over CoAP, and it might be a good fit for LPWAN techs 💅. The overhead gets reduced by adding a dictionary that matches a URI to a small identifier, plus a compact mapping of the YANG data model into the Concise Binary Object Representation (CBOR) 🧚♀️.
4.8. Mobility 🦋
LPWAN nodes can be mobile 🚶♀️. But LPWAN mobility is different from what's specified for Mobile IP 🙅♀️. LPWAN means sporadic traffic and it's rarely used for high-frequency, real-time communication 📭. The apps don't generate a flow; they need to save energy, and most of the time the node is just down 😴.
Also, LPWAN mobility may mostly apply to groups of devices that make up a network 🚐. In that case, mobility is more of a concern for the Gateway than for the devices 🌉. Network Mobility (NEMO) [RFC3963] or other mobile Gateway solutions (like a Gateway with an LTE uplink) may be used when some end devices in the same network Gateway move from one spot to another without being aware they're mobile 🗺️.
4.9. DNS and LPWAN 🌐
The Domain Name System (DNS) [RFC1035] lets apps name things with a globally resolvable name 🏷️. Lots of protocols use DNS to identify hosts, like apps using CoAP 💻.
Okay, this one's kinda problematic 😬. The DNS query/answer protocol, as a precursor to other communication within the Time-To-Live (TTL) of a DNS answer, is clearly a problem in an LPWAN, say where only one round-trip per hour can be used, with a TTL under 3600 seconds ⏳. It's still unclear whether and how DNS-like functionality could be provided in LPWANs 🤷♀️.
5. Security Considerations 🔐
Heads up, bestie, this part is SERIOUS 😭🔐. Read it all.
Most LPWAN technologies come with some authentication or encryption mechanisms that were defined outside the IETF 🙃. The LPWAN WG may need to do some work to integrate these mechanisms and unify management 🔗. A standardized Authentication, Authorization, and Accounting (AAA) infrastructure [RFC2904] may offer a scalable solution for some of the security and management issues in LPWANs 🛡️. AAA offers centralized management that could be useful in LPWANs 🧠. For example, [LoRaWAN-AUTH] and [LoRaWAN-RADIUS] suggest possible security processes for a LoRaWAN network 📜. Similar mechanisms might be worth exploring for other LPWAN techs too 👀.
Some apps using LPWANs may raise few or no privacy considerations 🌤️. For example, temperature sensors in a big office building may not raise privacy issues 🏢. But the same sensors deployed in a home, especially if they're triggered by human presence, can raise significant privacy issues 🏠😳. If an end device emits an (encrypted) packet every time someone walks into a room in a home, then that traffic is privacy sensitive 🚪. And the more that the existence of that traffic is visible to network entities, the more privacy sensitivities pop up 👁️. Right now, it's not clear whether there are workable mitigations for problems like this 😵💫. In a more typical network, you'd consider defining padding mechanisms and allowing for cover traffic 🎭. In some LPWANs, those mechanisms may not be feasible 💔. Still, the privacy challenges are real, and they can be really real, so some solutions will be needed ✊. Note that many aspects of solutions in this space may not be visible in IETF specifications, but they can be, e.g., implementation or deployment specific 🧩.
Another challenge for LPWANs is how to handle key management and associated protocols 🔑. In a more traditional network (e.g., the Web), servers can "staple" Online Certificate Status Protocol (OCSP) responses so browsers can check revocation status for presented certificates [RFC6961] 🌐. The stapling approach is likely something that would help in an LPWAN, since it avoids an RTT 🙌. But certificates and OCSP responses are bulky, so they'll be challenging to handle in LPWANs with bounded bandwidth 🐘💦.
6. IANA Considerations 📋
Good news, this document has no IANA actions 🎉✨.
7. Informative References 📚
[ANSI-4957-000]
ANSI/TIA, "Architecture Overview for the Smart Utility
Network", ANSI/TIA-4957.0000 , May 2013.
[ANSI-4957-210]
ANSI/TIA, "Multi-Hop Delivery Specification of a Data Link
Sub-Layer", ANSI/TIA-4957.210 , May 2013.
[arib_ref] ARIB, "920MHz-Band Telemeter, Telecontrol and Data
Transmission Radio Equipment", ARIB STD-T108 Version 1.0,
February 2012.
[ETSI-TS-102-887-2]
ETSI, "Electromagnetic compatibility and Radio spectrum
Matters (ERM); Short Range Devices; Smart Metering
Wireless Access Protocol; Part 2: Data Link Layer (MAC
Sub-layer)", ETSI TS 102 887-2, Version V1.1.1, September
2013.
[etsi_ref1]
ETSI, "Short Range Devices (SRD) operating in the
frequency range 25 MHz to 1 000 MHz; Part 1: Technical
characteristics and methods of measurement", Draft ETSI
EN 300-220-1, Version V3.1.0, May 2016.
[etsi_ref2]
ETSI, "Short Range Devices (SRD) operating in the
frequency range 25 MHz to 1 000 MHz; Part 2: Harmonised
Standard covering the essential requirements of article
3.2 of Directive 2014/53/EU for non specific radio
equipment", Final draft ETSI EN 300-220-2 P300-220-2,
Version V3.1.1, November 2016.
[etsi_unb] ETSI ERM, "System Reference document (SRdoc); Short Range
Devices (SRD); Technical characteristics for Ultra Narrow
Band (UNB) SRDs operating in the UHF spectrum below 1
GHz", ETSI TR 103 435, Version V1.1.1, February 2017.
[EUI64] IEEE, "Guidelines for 64-bit Global Identifier
(EUI),Organizationally Unique Identifier (OUI), and
Company ID (CID)", August 2017,
<http://standards.ieee.org/develop/regauth/tut/eui.pdf>.
[FANOV] IETF, "Wi-SUN Alliance Field Area Network (FAN) Overview",
IETF 97, November 2016,
<https://www.ietf.org/proceedings/97/slides/
slides-97-lpwan-35-wi-sun-presentation-00.pdf>.
[fcc_ref] "Telecommunication Radio Frequency Devices - Operation
within the bands 902-928 MHz, 2400-2483.5 MHz, and
5725-5850 MHz.", FCC CFR 47 15.247, June 2016.
[G9959] ITU-T, "Short range narrow-band digital radiocommunication
transceivers - PHY, MAC, SAR and LLC layer
specifications", ITU-T Recommendation G.9959, January
2015, <http://www.itu.int/rec/T-REC-G.9959>.
[IEEE.802.11]
IEEE, "IEEE Standard for Information technology--
Telecommunications and information exchange between
systems Local and metropolitan area networks--Specific
requirements Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications",
IEEE 802.11.
[IEEE.802.15.12]
IEEE, "Upper Layer Interface (ULI) for IEEE 802.15.4 Low-
Rate Wireless Networks", IEEE 802.15.12.
[IEEE.802.15.4]
IEEE, "IEEE Standard for Low-Rate Wireless Networks",
IEEE 802.15.4, <https://standards.ieee.org/findstds/
standard/802.15.4-2015.html>.[IEEE.802.15.4e] IEEE, "IEEE Standard for Local and metropolitan area networks--Part 15.4: Low-Rate Wireless Personal Area Networks (LR-WPANs) Amendment 1: MAC sublayer", IEEE 802.15.4e.
[IEEE.802.15.4g] IEEE, "IEEE Standard for Local and metropolitan area networks--Part 15.4: Low-Rate Wireless Personal Area Networks (LR-WPANs) Amendment 3: Physical Layer (PHY) Specifications for Low-Data-Rate, Wireless, Smart Metering Utility Networks", IEEE 802.15.4g.
[IEEE.802.15.9] IEEE, "IEEE Recommended Practice for Transport of Key Management Protocol (KMP) Datagrams", IEEE Standard 802.15.9, 2016, <https://standards.ieee.org/findstds/standard/802.15.9-2016.html>.
[IEEE.802.1AR] ANSI/IEEE, "IEEE Standard for Local and metropolitan area networks - Secure Device Identity", IEEE 802.1AR.
[IEEE.802.1x] IEEE, "Port Based Network Access Control", IEEE 802.1x.
[LoRaSpec] LoRa Alliance, "LoRaWAN Specification Version V1.0.2", July 2016, <https://lora-alliance.org/sites/default/files/2018-05/lorawan1_0_2-20161012_1398_1.pdf>.
[LoRaWAN] Farrell, S. and A. Yegin, "LoRaWAN Overview", Work in Progress, draft-farrell-lpwan-lora-overview-01, October 2016.
[LoRaWAN-AUTH] Garcia, D., Marin, R., Kandasamy, A., and A. Pelov, "LoRaWAN Authentication in Diameter", Work in Progress, draft-garcia-dime-diameter-lorawan-00, May 2016.
[LoRaWAN-RADIUS] Garcia, D., Lopez, R., Kandasamy, A., and A. Pelov, "LoRaWAN Authentication in RADIUS", Work in Progress, draft-garcia-radext-radius-lorawan-03, May 2017.
[LPWAN-GAP] Minaburo, A., Ed., Gomez, C., Ed., Toutain, L., Paradells, J., and J. Crowcroft, "LPWAN Survey and GAP Analysis", Work in Progress, draft-minaburo-lpwan-gap-analysis-02, October 2016.
[NB-IoT] Ratilainen, A., "NB-IoT characteristics", Work in Progress, draft-ratilainen-lpwan-nb-iot-00, July 2016.
[nbiot-ov] IEEE, "NB-IoT Technology Overview and Experience from Cloud-RAN Implementation", Volume 24, Issue 3 Pages 26-32, DOI 10.1109/MWC.2017.1600418, June 2017.
[RFC768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, <https://www.rfc-editor.org/info/rfc768>.
[RFC793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, DOI 10.17487/RFC0793, September 1981, <https://www.rfc-editor.org/info/rfc793>.
[RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, November 1987, <https://www.rfc-editor.org/info/rfc1035>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, December 1998, <https://www.rfc-editor.org/info/rfc2460>.
[RFC2904] Vollbrecht, J., Calhoun, P., Farrell, S., Gommans, L., Gross, G., de Bruijn, B., de Laat, C., Holdrege, M., and D. Spence, "AAA Authorization Framework", RFC 2904, DOI 10.17487/RFC2904, August 2000, <https://www.rfc-editor.org/info/rfc2904>.
[RFC3095] Bormann, C., Burmeister, C., Degermark, M., Fukushima, H., Hannu, H., Jonsson, L-E., Hakenberg, R., Koren, T., Le, K., Liu, Z., Martensson, A., Miyazaki, A., Svanbro, K., Wiebke, T., Yoshimura, T., and H. Zheng, "RObust Header Compression (ROHC): Framework and four profiles: RTP, UDP, ESP, and uncompressed", RFC 3095, DOI 10.17487/RFC3095, July 2001, <https://www.rfc-editor.org/info/rfc3095>.
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 2003, <https://www.rfc-editor.org/info/rfc3315>.
[RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, DOI 10.17487/RFC3963, January 2005, <https://www.rfc-editor.org/info/rfc3963>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, DOI 10.17487/RFC4301, December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", STD 89, RFC 4443, DOI 10.17487/RFC4443, March 2006, <https://www.rfc-editor.org/info/rfc4443>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 10.17487/RFC4861, September 2007, <https://www.rfc-editor.org/info/rfc4861>.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, "Transmission of IPv6 Packets over IEEE 802.15.4 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007, <https://www.rfc-editor.org/info/rfc4944>.
[RFC5216] Simon, D., Aboba, B., and R. Hurst, "The EAP-TLS Authentication Protocol", RFC 5216, DOI 10.17487/RFC5216, March 2008, <https://www.rfc-editor.org/info/rfc5216>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, August 2008, <https://www.rfc-editor.org/info/rfc5246>.
[RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, DOI 10.17487/RFC5280, May 2008, <https://www.rfc-editor.org/info/rfc5280>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, DOI 10.17487/RFC6282, September 2011, <https://www.rfc-editor.org/info/rfc6282>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. Bormann, "Neighbor Discovery Optimization for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)", RFC 6775, DOI 10.17487/RFC6775, November 2012, <https://www.rfc-editor.org/info/rfc6775>.
[RFC6961] Pettersen, Y., "The Transport Layer Security (TLS) Multiple Certificate Status Request Extension", RFC 6961, DOI 10.17487/RFC6961, June 2013, <https://www.rfc-editor.org/info/rfc6961>.
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained Application Protocol (CoAP)", RFC 7252, DOI 10.17487/RFC7252, June 2014, <https://www.rfc-editor.org/info/rfc7252>.
[RFC7452] Tschofenig, H., Arkko, J., Thaler, D., and D. McPherson, "Architectural Considerations in Smart Object Networking", RFC 7452, DOI 10.17487/RFC7452, March 2015, <https://www.rfc-editor.org/info/rfc7452>.
[RFC7668] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B., Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015, <https://www.rfc-editor.org/info/rfc7668>.
[RFC8065] Thaler, D., "Privacy Considerations for IPv6 Adaptation-Layer Mechanisms", RFC 8065, DOI 10.17487/RFC8065, February 2017, <https://www.rfc-editor.org/info/rfc8065>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, <https://www.rfc-editor.org/info/rfc8200>.
[RFC8240] Tschofenig, H. and S. Farrell, "Report from the Internet of Things Software Update (IoTSU) Workshop 2016", RFC 8240, DOI 10.17487/RFC8240, September 2017, <https://www.rfc-editor.org/info/rfc8240>.
[Sigfox] Zuniga, J. and B. PONSARD, "Sigfox System Description", Work in Progress, draft-zuniga-lpwan-sigfox-system-description-04, December 2017.
[TGPP23720] 3GPP, "Study on architecture enhancements for Cellular Internet of Things", 3GPP TS 23.720 13.0.0, 2016.
[TGPP33203] 3GPP, "3G security; Access security for IP-based services", 3GPP TS 23.203 13.1.0, 2016.
[TGPP36201] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA); LTE physical layer; General description", 3GPP TS 36.201 13.2.0, 2016.
[TGPP36300] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2", 3GPP TS 36.300 13.4.0, 2016, <http://www.3gpp.org/ftp/Specs/2016-09/Rel-14/36_series/>.
[TGPP36321] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification", 3GPP TS 36.321 13.2.0, 2016.
[TGPP36322] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Link Control (RLC) protocol specification", 3GPP TS 36.322 13.2.0, 2016.
[TGPP36323] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA); Packet Data Convergence Protocol (PDCP) specification (Not yet available)", 3GPP TS 36.323 13.2.0, 2016.
[TGPP36331] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification", 3GPP TS 36.331 13.2.0, 2016.
[USES-6LO] Hong, Y., Gomez, C., Choi, Y-H., and D-Y. Ko, "IPv6 over Constrained Node Networks(6lo) Applicability & Use cases", Work in Progress, draft-hong-6lo-use-cases-03, October 2016.
[wisun-pressie1] Beecher, P., "Wi-SUN Alliance", March 2017, <http://indiasmartgrid.org/event2017/10-03-2017/4.%20Round%20table%20on%20Communication%20and%20Cyber%20Security/1.%20Phil%20Beecher.pdf>.
[wisun-pressie2] Heile, B., "Wi-SUN Alliance Field Area Network (FAN)Overview", As presented at IETF 97, November 2016, <https://www.ietf.org/proceedings/97/slides/slides-97-lpwan-35-wi-sun-presentation-00.pdf>.
Acknowledgments ✨
okay bestie, time for the thank-you section 🫶 huge thanks to everyone in the Contributors section for the excellent text 💖 any mistakes in how that all got handled are 100% the editor's fault 😭
also big thanks to these lovelies, listed alphabetically, for their comments 🌸
- Abdussalam Baryun
- Andy Malis
- Arun (arun@acklio.com)
- Behcet SariKaya
- Dan Garcia Carrillo
- Jiazi Yi
- Mirja Kuhlewind
- Paul Duffy
- Russ Housley
- Samita Chakrabarti
- Thad Guidry
- Warren Kumari
Alexander Pelov and Pascal Thubert were the LPWAN WG Chairs while this document was developed. 🧚
Stephen Farrell's work on this memo was supported by Pervasive Nation, the Science Foundation Ireland's CONNECT centre national IoT network <https://connectcentre.ie/pervasive-nation/>. 🌈
Contributors 💜
okay so this document is mainly a collection of content written by the whole squad of contributors listed below 🫶 the main input documents and who wrote them:
- Text for Section 2.1 was provided by Alper Yegin and Stephen Farrell in [LoRaWAN].
- Text for Section 2.2 was provided by Antti Ratilainen in [NB-IoT].
- Text for Section 2.3 was provided by Juan Carlos Zuniga and Benoit Ponsard in [Sigfox].
- Text for Section 2.4 was provided via personal communication from Bob Heile and was authored by Bob and Sum Chin Sean. There is no Internet-Draft for that at the time of writing. 🦋
- Text for Section 4 was provided by Ana Minabiru, Carles Gomez, Laurent Toutain, Josep Paradells, and Jon Crowcroft in [LPWAN-GAP]. Additional text from that document is also used elsewhere above. ✨
the full list of contributors is below, with their contact details exactly as given 💅
Jon Crowcroft
University of Cambridge
JJ Thomson Avenue
Cambridge, CB3 0FD
United Kingdom
Email: jon.crowcroft@cl.cam.ac.ukCarles Gomez
UPC/i2CAT
C/Esteve Terradas, 7
Castelldefels 08860
Spain
Email: carlesgo@entel.upc.eduBob Heile
Wi-Sun Alliance
11 Robert Toner Blvd, Suite 5-301
North Attleboro, MA 02763
United States of America
Phone: +1-781-929-4832
Email: bheile@ieee.orgAna Minaburo
Acklio
2bis rue de la Chataigneraie
35510 Cesson-Sevigne Cedex
France
Email: ana@ackl.ioJosep PAradells
UPC/i2CAT
C/Jordi Girona, 1-3
Barcelona 08034
Spain
Email: josep.paradells@entel.upc.eduCharles E. Perkins
Futurewei
2330 Central Expressway
Santa Clara, CA 95050
United States of America
Email: charliep@computer.orgBenoit Ponsard
Sigfox
425 rue Jean Rostand
Labege 31670
France
Email: Benoit.Ponsard@sigfox.com
URI: http://www.sigfox.com/Antti Ratilainen
Ericsson
Hirsalantie 11
Jorvas 02420
Finland
Email: antti.ratilainen@ericsson.comChin-Sean SUM
Wi-Sun Alliance
20, Science Park Rd 117674
Singapore
Phone: +65 6771 1011
Email: sum@wi-sun.orgLaurent Toutain
Institut MINES TELECOM ; TELECOM Bretagne
2 rue de la Chataigneraie
CS 17607
35576 Cesson-Sevigne Cedex
France
Email: Laurent.Toutain@telecom-bretagne.euAlper Yegin
Actility
Paris
France
Email: alper.yegin@actility.comJuan Carlos Zuniga
Sigfox
425 rue Jean Rostand
Labege 31670
France
Email: JuanCarlos.Zuniga@sigfox.com
URI: http://www.sigfox.com/Author's Address 🎀
Stephen Farrell (editor) is the editor who kept everything together, so here are the details exactly as written 🥰
Stephen Farrell (editor)
Trinity College Dublin
Dublin 2
Ireland
Phone: +353-1-896-2354
Email: stephen.farrell@cs.tcd.ie📦 where this page comes from
- ietf: rfc8376 2018-05
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms