Cost

Traditional LTE end devices have complex modulation and antenna requirements which mean that they are relatively expensive. The new generation on LPWAN devices have a number of enhancements which have drastically reduced this.

Range

The range of 5G is as little as 300 metres from a cell tower. The range of older cellular technologies is higher than this, but LPWAN technologies – especially LoRaWAN, SigFox, NB-IOT and LTE-M all have a far higher link budget (typically 155-180dB) than traditional ‘smartphone based’ cellular. Therefore, they have a far higher range (832km is world record for LoRaWAN!).

Bandwidth & Data Rate

One of the key factors in increasing the range while keeping the cost down is data rate. The vast majority of the billions of IoT devices in existence today send and receive very little data.

5G however is tipped to be an IoT game changer (by everyone who has an interest in it) – and I’m sure this will be true for certain high bandwidth applications.

However, this section is focused heavily on low bandwidth IoT, and for these technologies, reducing the data rate is a key compromise which enables all the other factors to fall in to place.

Power & Device Battery Life

New battery technologies are also a key driving force between the rise of IoT. By far the most common battery types used in IoT devices are Lithium. There are various types of Lithium devices, but they are generally light and compact batteries with very high energy density and high voltage. Many batteries have a maximum lifetime of 10 years, and battery life longevity is a critical requirement for many installations.

Reference: https://www.saftbatteries.com/energizing-iot/types-batteries-iot-devices/

Network Infrastructure & Cloud applications

There is not much point collecting data from a sensor if you can’t visualise, analyse and take actions that add value – i.e. save money, time or generate revenue.

This another area where there is a quantum leap forward in recent years. There are now LPWAN networks, IoT core platforms and application platforms provided by many companies which all have aim to enable you to get value from your data. Without these, IoT would be pretty dull..

With the cellular technologies – LTE-M and NB-IOT, the end devices communication directly with the network.

For these technologies, the Comms Network above refers to the LTE RAN equipment and the LTE Core.

Some technologies (such as LoRaWAN) require a gateway to make the leap from the LPWAN technology to the backhaul. In this case, the backhaul depends on the gateway.

For instance, a LoRaWAN to LTE 4G gateway will route the traffic to the LTE RAN (where it will then follow the same route as an NB-IOT or LTE-M traffic).

However a LoRaWAN to WiFi gateway routes traffic via the fixed line network (usually via an Internet Service Provider (ISP)).

The gateway could be seen as local equipment (which is often in the same building as the sensors), or as part of the Radio Access Network – as in the case of public access LoRaWAN networks such as Everynet or Loriot.

To summarise, the comms network above consists of some or all of the following:

• The Gateway
• The Radio Access Network or ISP access fixed line equipment
• The Core network (e.g. LTE core)
• The LPWAN network equipment

It consists of entities which control packet data routing and forwarding, device registration, security, network management and many other functions.

LTE is a subset of cellular networks. The first LTE release was 3GPP Release 8 (December 2008). The number of technologies, categories and terms under the LTE is fairly bewildering.

In brief,

• 4G is LTE Cat 1-5, 3GPP Release 8, 2009
• 4G LTE-A is LTE Cat 6-8, Release 10
• 5G is Cat 9, Release 11.
• NB-IOT (LTE Cat-NB1) and LTE-M (LTE Cat-M1) were were released in Release 13.

Below is a summary of the carious LTE LPWAN technologies from everybody’s favourite: https://en.wikipedia.org/wiki/LTE-M.

And for everything you ever wanted to know about LTE categories…

The technologies are compared and contrasted in the next section. But before we get to that, these are the key user requirements (relative to standard LTE technologies) and a brief summary of how they are achieved.

• Lower cost (including device cost and network access charges)
  • Reduced RF Bandwidth
  • Single antenna, MIMO not supported
  • Reduced uplink transmit power
  • Single Radio Access Technology supported (i.e. LTE)
• Extended battery life
  • Power saving mode
  • Extended DRX cycle (NB-IOT only)
• Lower data requirements
  • NB-IOT supports 60-200Kbps (at least 10x less than 4G)
  • LTE-M supports 300kbps-1Mbps
• Extended coverage
  • Reduced bandwidth means increased link budget (~155dB)
• Massive deployment
  • High order modulation (see table below)
  • For NB-IOT, around 55,000 end devices can be supported per cell.

Transmission over air

LTE-M uses far more bandwidth than NB-IOT, so it’s less flexible from a network operators point of view.

NB-IOT requires a minimum 200kHz bandwidth (uplink & downlink), and can be transmitted over the LTE/GSM network in one of three ways:

• In-Band LTE
• Guard Band LTE
• Standalone in a GSM carrier

LTE-M vs NB-IOT

LTE-M and NB-IOT were both released by GPP at the same time as NB-IOT (3GPP Release 13).

LTE-M has a higher data rate, better mobility, better latency and potentially better battery life (due to the reduced transmit time on air for the same amount of data). LTE-M also supports voice, and is designed for IP whereas NB-IOT wasn’t originally envisioned to send IP packets.

As a brief comparison:

Or if you would like slightly more detail…

NB-IOT has better performance for low data rate stationary use cases, especially where extended coverage is required – eg. indoors, or underground. LTE-M would be a better choice for higher data rates – but certainly not video, where mobility is required. The GSMA has a reliable independent comparison of data rate and latency.

NB-IoT is designed to support IoT devices that operate in deep indoor or remote areas [1]. To satisfy these requirements the Release 13 enhancement introduces a set of techniques for improving coverage by taking advantage of the relaxed IoT requirements regarding data rate and latency. The improvement is estimated as a +20dB gain when compared to General Packet Radio Service (GPRS), which corresponds to a Maximum Coupling Loss (MCL) of 164dB.

To achieve this gain, two main mechanisms are introduced in repetitions and the ability to allocate variable bandwidth through the use of multi-tone operation.

https://arxiv.org/pdf/1810.00847.pdf

In the real world, either technology will work fine for the vast majority of low data rate IoT use cases, and your choice will really come down to two things:

• Your preferred supplier / device.
• Network Coverage – note that globally NB-IOT is supported by twice as many networks as LTE-M. See the maps below and this global coverage map.

i.e. If the device has the right feature set, and the supplier provides the right level of service and you have network coverage – then these are highly likely to much more important factors than the technology choice.

For reasons regarding accessibility and ease of deployment, LTE-M hasn’t experienced nearly the same growth rate as NB-IoT across many developed countries (and is more concentrated in the North American area):

https://ubidots.com/blog/nb-iot-vs-lte-m/

For a short entertaining video on the differences between the two, check out the video below.

Further reading:

• https://ubidots.com/blog/nb-iot-vs-lte-m/
• https://www.iotforall.com/cellular-iot-explained-nb-iot-vs-lte-m
• https://www.netmanias.com/en/post/blog/12609/iot-nb-iot/nb-iot-data-rates-and-latency

• GSMA NB-IOT Deployment guide
• GSMA LTE-M Deployment guide

4G & 5G

This site won’t cover these detail. 4G is fast, 5G is faster. 4G is expensive, 5G is more expensive. Interestingly, 4G has a range of around 10 miles, whereas 5G has a range of around 300 metres – or around 2% of 4G’s range. So 5G needs a lot more base base stations to cover the same area.

4G is also known as LTE or LTE-Advanced (LTE-A). 5G is not LTE – it’s one step beyond..

The graph shows the historic and forecast coverage for 4G LTE and 5G.

2G & 3G

2G and 3G are both very much legacy technologies. However, there important regional differences when it comes to IoT – when they will be switched off (or ‘sunset’).

As a rough guide, Europe is switching 3G off first. 2G will be on until at least 2025, and the reason for this is IoT. A lot of devices – especially smart meters have been deployed using 2G and switching it off would cause chaos. 3G isn’t used to any notable extent for IoT and doesn’t give any benefits over 4G, so it will be switched off first.

In other parts of the world, 2G has either already been switched off or will be switched off first. See below for details:

https://www.digi.com/blog/post/upcoming-2g-and-3g-global-cellular-network-sunset

In general, if you are considering 2G or 3G for a new deployment – stop right now, and think again. If you have it installed already, then you need to be aware of sunset dates in the link above and start planning for a move to a newer technology – and to be future proof, you should either be considering 5G or LTE-M (which is generally accepted as the IoT world’s replacement for 2G).

LPWAN

Low Power Wide Area Networks (LPWAN) are what most people think of as IoT today. The major players in non-cellular are LoRaWAN and SigFox.

LoRa & LoRaWAN

LoRaWAN (which is based on LoRa) is arguably the most disruptive IoT technology on the market.

It’s low startup cost and long range are major factors in it’s success. The driving forces behind the adoption of LoRaWAN are the LoRa alliance and ‘The Things Network (TTN)‘ – a free to use community based LoRaWAN network.

For a detailed description of LoRa & LoRaWAN technologies, click here.

SigFox

SigFox has many similar characteristics to LoRaWAN. However, the network is privately owned and operated by a private company. It is however widely available in Europe and a number of other territories.

WiFi HaLow

Wi-Fi HaLow™, the designation for products incorporating IEEE 802.11ah technology, augments Wi-Fi by operating in spectrum below one gigahertz (GHz) to offer longer range and lower power connectivity. Wi-Fi HaLow meets the unique requirements for the Internet of Things (IoT) to enable a variety of use cases in industrial, agricultural, smart building, and smart city environments.

Wi-Fi HaLow enables the low power connectivity necessary for applications including sensor networks and wearables. Its range is longer than many other IoT technology options and it provides a more robust connection in challenging environments where the ability to penetrate walls or other barriers is an important consideration.

Other LPWAN technologies

• Weightless & Symphony Link
• Dash7

Short Range

Zigbee

Zigbee is a a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios, such as for home automation, medical device data collection, and other low-power low-bandwidth needs, designed for small scale projects which need wireless connection. Hence, Zigbee is a low-power, low data rate, and close proximity (i.e., personal area) wireless ad hoc network.

For more info, see the Zigbee alliance.

WiFi

Wi-Fi is a family of wireless networkprotocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access. Wi‑Fi is a trademark of the non-profit Wi-Fi Alliance

Bluetooth Low Energy (BLE)

Bluetooth Low Energy is unsurprisingly a low energy version of bluetooth, but there is more to it than that.

RFID & NFC

RFID and NFC are global wireless or rather contactless communication technologies.

RFID stands for Radio-Frequency Identification. RFID technology enables the communication between an unpowered tag and a powered reader.

RFID systems consist of a reader with an antenna, and a transponder (tag). There are two different RFID tags possible. Either they are active, meaning they have their own power source or they are passive. Passive tags have no own power source and have to be supplied with energy via an electromagnetic field produced by the reader.

Passive transponders or tags are available in three different RFID frequency ranges: Low frequency (LF), high frequency (HF) and ultra high frequency (UHF). The reading range of LF and HF systems is usually only a few centimeters. UHF tags, however, are often readable over distances of more than one meter.

RFID is best suited for asset tracking and location in logistic functions.

NFC stands for Near-Field Communication. NFC is also based on the RFID protocols. The main difference to RFID is that a NFC device can act not only as a reader, but also as a tag (card emulation mode). In peer-to-peer mode, it is also possible to transfer information between two NFC devices.

NFC systems operate on the same frequency as HF RFID (13.56 MHz) systems. Therefore, there are only short read range limitations.

Because of the short read range limitations, NFC devices have to be in very close proximity – usually no more than a few centimeters. That’s why NFC is often used for secure communications, especially for access controls or in the consumer sector for contactless payment.

Ref: Ecom-Ex