One of the major obstacles holding back the mass rollout of M2M/IoT applications has been the lack of an accepted standard for low-power wide area networks. But now there’s a number of options available with more in the works. James Atkinson looks at what’s on offer
Until recently, end users of machine-to-machine (M2M) and Internet of Things (IoT) applications have largely had to rely on either wired or licensed cellular connectivity solutions provided by mobile network operators (MNOs).
A number of companies and industry bodies are working to meet these challenges. These can be divided into solutions developed by start-ups ranging from free, fully-open standards to proprietary or semi-proprietary ones, and then there’s a number of options being looked at by standards body 3GPP in the licensed cellular space – most of which are derivations of 4G LTE.
If you want an LPWAN solution right now that meets the above criteria you are not going to find it on licensed spectrum. This has given the independents a first-mover advantage. The main contenders are: France’s Sigfox; the LoRa (Long Range) Alliance, spearheaded by California-based Semtech Corporation; Ingenu (until recently known as On-Ramp Wireless), also based in California; and the Weightless Special Interest Group (SIG).
The RPMA technology supplies a full two-way link, and the company describes its raison d’être as being about providing better coverage (it claims its towers can cover more than 200 sq miles), but not faster speeds when compared with existing cellular networks. Ingenu has raised more than $100 million in funding to date.
The LoRa Alliance was formed in January this year as an ‘open, non-profit association of members’. In June 2015, it released the LoRaWAN R1.0 specification. This uses a modulation format based on Chirp Spread Spectrum (CSS), which is widely used in radar and ranging applications, but not commonly deployed in communication systems because of its susceptibility to interference.
Another player operating under the LoRa Alliance standard is Link Labs, but it has also developed a proprietary system to provide more advanced functionality called Symphony Link. It uses the LoRa physical layer, but not the stnadard LoRaWAN MAC architecture.
Weightless-P is the SIG’s latest variant, which is being developed on the back of Taiwanese company M²COMM’s decision to open its IPR up. This is a full two-way link, ultra-high performance LPWAN solution using ISM/SRD bands with an adaptive data rate ranging from 200bps to 100kbps. Base stations, endpoints and development kits are expected to be commercially available in Q1 2016.
Most of these solutions have the advantage of being available right now, but they do have some disadvantages. Jamie Moss, principal analyst, consumer technology & Internet of Things at Ovum, observes: ‘It is very hard for small start-up vendors, especially proprietary ones, to gain acceptance because it requires a lot of faith to buy into a new ecosystem and believe that it will be there in the future.
‘I think that these kind of companies start up for the sake of being acquired by established players once their offering is fully formed, and they can then be integrated into the market via a well-known manufacturer, who everyone knows and trusts will be around for a long time. Neul was a good example of this, being snapped up by Huawei,’ says Moss.
‘The Weightless SIG approach of providing fully open standards is an interesting way to go to market by making it all free. I think they are hoping that the likes of Ericsson or Huawei might pick it up and run with it and give the market confidence in the standard and start to get orders,’ he suggests.
The first approach being worked on by 3GPP is to take the LTE standard and adapt it to meet the LPWAN aspirations outlined earlier – referred to as LTE-MTC (machine type communication). The starting point is LTE Release 8 Category 1 (Cat-1) where devices have a downlink peak rate of 10mbps (uplink 5mbps) and are full duplex.
It will also be the first to provide a reduced device-receive bandwidth of 1.4MHz, compared with 20MHz for Categories 4, 1 and O – this is where the main cost reduction comes from. In other words, the LTE spectrum is transmitted in narrower slices, making better use of limited spectrum.
Further reductions to just 200kHz, narrow band in other words, are also being studied, although a 2014 white paper, LTE Evolution for Cellular IoT by Ericsson and Nokia Networks concluded: ‘Introduction of a narrower LTE system bandwidth (eg. 200kHz) can be considered but requires substantial additional efforts to the improvement listed above (ie. those envisaged by Rel.12 and 13).’
As regards timelines for commercial deployment, the major M2M module providers u-blox, Gemalto’s Cinterion and Telit – working with chipset provider Altair – have only just unveiled their first commercially available Cat-1 IoT modules this month (September 2015), while Sierra Wireless’ first Cat-1 module is due shortly. However, commercial deployment of Cat-0 is not expected until 2017 and Cat-M in 2018.
But not everyone is convinced that taking a standard designed for high power, high data rate transmission is the best approach to finding a cellular LPWAN. This has led to the so-called ‘Clean Slate’ solutions, which have split into two camps: NB-LTE (Narrow Band LTE); and NB-CIoT (Narrow Band Cellular Internet of Things).
Huawei and its acquisition Neul argue in a white paper entitled "Introduction to ‘Clean-Slate’ Cellular IoT radio access solution" that: ‘These benefits (ie. the LPWAN criteria set out above) are very hard to achieve through the evolution of existing cellular radio access technologies’ and that this is ‘because the IoT requirements are so different from mobile broadband’.
Regarding the various cellular options, Daryl Schoolar, principal analyst, Intelligent Networks at Ovum, says: ‘I think there is a real possibility that Cat-0 might be skipped over for Cat-M. Cat-1 should be available end of this year. Cat-M availability should be in 2017-18, so why bother with Cat-0 in between?
‘The big obstacle I see with the clean slate option is that it requires new infrastructure investment, while what Ericsson, Nokia and Intel are proposing is a software update, which seems like a better prospect for mobile operators than buying more radios.’
Professor William Webb, CEO, Weightless SIG, observes: ‘There’s now a whole range of LPWAN standards, and things are getting worse rather than better and I think it is a terrible thing. We need a dominant short range and long range IoT standard. It is unfortunate that we haven’t got a dominant standard at the start that everyone can adopt, add their IPR and make money.’
Webb’s view is that while the proprietary standards may have first-mover advantage and are clearly fulfilling a need, they are unlikely to survive long term. ‘If you look at the history of wireless, the only successful technologies are open standard. There are no examples of proprietary ones being very successful, so I can’t see how the proprietary LPWAN vendors can last long term unless they morph into open standards.’
He points out that this is exactly what has happened with Weightless. UK firm NWave Technologies joined in October 2014 and Taiwanese firm M²Communication (M²COMM) in July 2015, with both deciding to make their IPR available to all by joining Weightless. ‘In effect they said: we won’t get this to work if we stay proprietary, so we’ll gift our technology to an open standard,’ says Webb.
M²COMM developed its proprietary Platanus protocol largely to target high densities of end devices (up to 10,000) in short-range environments, such as thousands of RFID tags in retail spaces.
Fabien Petitgrand, a member of the technical staff at M²COMM, explains: ‘We developed a pretty closed and proprietary application, but we wanted to go beyond that and move to longer-range outdoor applications for smart cities and so on. But we needed to add some kind of standard for interoperability, so we got in touch with Weightless SIG.
‘The benefit for us is that there are more parties involved, so you design a better standard and we can still be first to market with hardware and software, because we created it and so get a first-mover advantage.’
‘For us it is really about capacity; the ability to handle the growing number of devices needing to communicate some data on the uplink. You need to get as many users as possible in one hour on the uplink. We are not seeing capacity issues in M2M yet as there is very little deployment, but we know from the cellular experience that this will become the main problem.’
He continues: ‘In unlicensed bands you also have to deal with other users you cannot control. Some will be narrow band and some wide band, but what it means is your noise level cannot be controlled as other users will be using the same spectrum. That means your range gets hit and therefore you cannot guarantee the range in those circumstances.
‘We are looking at narrow band, rather than ultra narrow band to try to guarantee better reliability. I don’t think the 20db increase in coverage aspiration is the point. It is not about achieving x km more. We are shooting for capacity and reliable communications, rather than trying to hit the longer range, so that is what Weightless-P is mostly about.’
Petitgrand says M²COMM looked at cellular options, but observes: ‘It is a longer path via 3GPP to reach licensed IoT LPWAN standards. Of course it will happen and we will play in that space for sure and we are designing Weightless-P in that spirit.’
Ovum’s Jamie Moss is less worried by the proliferation of LPWAN standards. ‘It is not a case of either having to use LTE or a narrow band option; it could be anything in between. What we want is to have everything we need to supply the market at large. Some standards may be too narrow band for some applications, but if we have a granular availability of categories at the right price point that will give the market a wide range of possible options.
‘It’s all about providing effectiveness and efficiency,’ argues Moss, ‘so if an enterprise wants to improve its processes to be more effective, more efficient and reduce its costs, it has a solution available. If the solution does not enable this to happen there is no business case.’
Olivier Beaujard, vice president market development at Sierra Wireless, sits somewhere in between. ‘There are multiple candidates for LPWAN, but we do not believe only one technology will dominate as there are so many different applications, so you’ll never get one that works well for everything.’
Sierra Wireless is not working with the proprietary independent providers, however. ‘We work with the different working groups in 3GPP and GSMA so after we can share the same alignment on standardisation. We do believe that IoT has to be standardised if we want a massive spread across different industries.
‘But we think there will be more than one winner. We are following all of the options in the standardisation process, but where we are pushing the most and guiding our road map is the LTE-MTC family. We are contributing to the others too – some just to see what is happening, as we may need to react to more than one family of products.’
He says that Sierra is more sceptical about investing in the narrow band options such as Sigfox. ‘We see them more as proprietary solutions and the disadvantage they have is that you have to deploy a completely new network, while the LTE-MTC family means you can reuse existing infrastructure. That said: we could have partners who might develop partnerships with them combining cellular and narrow band options.’
Beaujard adds that Sierra is not concerned that LTE-O won’t be ready until 2017 and LTE-M until 2018, as the company believes the key verticals it is targeting, such as the utilities market, are not ready either.
‘It is a long process for them, so we are not late for the type of market we are addressing. You can start with LTE Cat-1 and then move to Cat-O. We use the same form factors for our modules for 2G, 3G and 4G and we will do the same for whatever low-power solution emerges: that’s very important for migration,’ says Beaujard. ‘We need the MNO networks in place too. It is a roadmap alignment for them, so we need to make sure we are not too early or too late for their alignment.’
It’s a pattern followed by the big M2M module providers Cinterion, Telit and Sierra Wireless, although Moss says they are likely to face increased competition from the likes of Huawei and ZTE, who are keen to break into this market.
‘They are going down the route of providing the cheapest possible module shipped in the greatest possible volumes to achieve economies of scale; they are talking about shipping in the millions and are earnestly pursuing this market. Huawei is developing its own modules and chipsets,’ points out Moss.
Weightless SIG’s William Webb says: ‘Our initial assumption was that it would be the operators who would build IoT networks, as they already have the masts, management and back office systems. But having dealt with them for a long time I’m not sure about that any more. They are big businesses focused on delivering services to consumers, and moving from a business that makes billions from consumer services to IoT that might only make them millions may not be that attractive.
‘It might happen though,’ he concedes, ‘but my take is that we will see other companies deliver IoT networks first, and if they are successful and make traction, then the MNOs might buy them up. If you look now it is the likes of Arqiva, Sigfox and BT too, of course, that will probably lead the way.
‘We need something to drive it forward with some companies to take the early pain because they can see the benefit of doing that. It might be a commercial organisation, but I don’t quite see who yet. Or it might be some other entity such as a government wanting to drive smart cities – and that’s not a bad place to start,’ says Webb.
Ovum’s Moss thinks the MNOs may play a bigger part than some anticipate. ‘The thing is people think the MNOs are just one-trick ponies with cellular, but they are service providers. They want to supply everyone, so they must be as flexible as possible and offer everything that is necessary. If they appreciate there is a level of demand for something they don’t have, they might roll out completely different networks.’
Webb says: ‘We are moving to a world where people are starting to make these kinds of investments, but it is a hard one to call as to who and what will emerge on the back of what applications. It is quite a risk.’
