For understandable reasons, most attention regarding LTE progression tends to focus on the sort of technical features that will boost capacities and decrease latencies across the network. I’m thinking of those items that are about enabling Carrier Aggregation, interference cancellation, HetNet co-ordination, increased antenna arrays and so on.
But LTE as a technology is also travelling in another direction. If the “more features enabling more bandwidth” path represents a vertical deepening of LTE’s capabilities, you might call this other direction a horizontal expansion. That is because this direction of travel sees LTE radio technology being used for something other than increased cellular capacities, but instead utilises (in the proper meaning of that word) LTE for a wider range of applications. Although these may be niche use cases, I think they are interesting to keep an eye on for three main reasons.
- They offer a chance for operators to make more money from an asset they have already deployed (the LTE network). For little extra outlay operators have a chance to open up new revenue opportunities.
- They offer a chance for operators to genuinely work in “partnership” with other players from within the tech/mobile industry. Win-win partnerships with developers/content owners etc. is a topic that we hear a lot about but so far with little evidence of progress.
- They could offer a “defensive” play against what carriers view as encroachment on their service repertoire, or enable certain carriers to “disrupt” their competitors in fixed and mobile.
The LTE expansion technologies that I think are interesting are these:
Comparable to Wi-Fi Direct in terms of concept, LTE Direct sets up a direct between users. Proponent Qualcomm says the technology has ultra-low power consumption on the device and offers ultra-low latency, with a range of 500m depending on propagation conditions. It claims that performance enables a content provider or advertiser to very quickly reach more than 1,000 devices without affecting the capacity of the network, as the tech uses just 0.3% of the 5MHz assigned to discovery mode.
Uses could include the broadcast of short amounts of local information, shared between devices that are listed in their preference profile as being interested in that content, and happy to receive that info. Once discovered, devices have the ability to exchange parameters, which users list as a set of preferences.
Deutsche Telekom has committed to a trial of the tech, and Qualcomm sees the potential for local advertising, marketing and loyalty partnerships.
To give it its 3GPP title, eMBMS is cell broadcast for LTE, standardised within Release 9. Cell broadcast may be an idea that never took off previously, but now the technology is being seriously considered by operators as a means of delivering content to large amounts of users in the same place.
A principal use case could be within and around stadiums for major sporting and music events. Operators have realised that the most viewed content by people attending a match is people watching coverage of the event they are at! [Really? Ed.]
LTE Broadcast is not likely to be something that operators roll out across all their sites – rather a chosen few where the demand profile meets a business case. Think of this in terms of partnerships – the broadcaster knows that there is a dedicated content delivery method for its lovely footage. The stadium or festival owner can run streams of replays, player-tracker, different angles etc. – adding to the “in game experience” of fans and customers. The operator gets to provide a “differentiated” experience at the game. Although some DAS systems at stadia are neutral host or multi-operator, an LTE Broadcast could go “over the top” – providing a better experience for customers of the operator providing the broadcast.
LTE Broadcast still requires device support obviously, and a few tinkerings in the core network, but in network terms implementation need not be massively disruptive for operators. Telstra conducted an in-stadium six-channel trial during a cricket match in Australia, with equipment from Ericsson. Verizon and Alcatel-Lucent showcased a more limited demo during the SuperBowl. EE has said it will trial the tech at an event (thought to be the Commonwealth Games) during 2014 and Ericsson has recently announced a live trial of the technology at a football match in The Netherlands, with KPN the host operator.
TDD-LTE for backhaul
Vodafone has had an interesting trial running in Madrid and Barcelona that has enabled it to provide flexible backhaul to small cells sited within the cities by using its TDD-LTE spectrum. One of the “stoppers” for small cell deployments is that there tends to be a pay off between ideal site location, which needs to be tightly defined to meet the concentration of users an operator is addressing, and the ability to get backhaul to the actual small cell. Using TDD-LTE for backhaul enables an operator to get some value out of its unpaired spectrum, but more importantly offers the chance to remove a key cost and logistical barrier to denser network deployments.
Small cells themselves, of course, are very much a line in the “increased capacity” checklist for operators, but what I am interested in for the purposes of this blog post is innovative uses of LTE, and I think this hits the mark.
The ‘U’ stands for Unlicensed, and this one is proving controversial. Essentially, the idea is to add a downlink channel to LTE from within unlicensed Wi-Fi frequencies—essentially carrier aggregation—but between licensed and unlicensed bands. This would give a boost to capacity, without requiring operators to compete for and invest in additional spectrum. Or it could give a boost to coverage of Wi-Fi, by in effect extending a Wi-Fi access point’s coverage.
Carrier Wi-Fi requires operators to deploy cells that operate in licensed and unlicensed spectrum, and then manage connectivity, authentication and mobility from core systems that can “see” both properties. One theory is that LTE deployed in unlicensed spectrum would enable operators to deploy from existing equipment, although there are hoops to jump through in terms of resource management within LTE compared to how Wi-Fi does things.
Each of these technologies is in a different state of readiness. Broadcast is defined and being trialled in live deployments. LTE-U is still in discussion stage. But I think if you view each in terms of how they can add value to an operator’s business as well as network operations, you can arrive at an awareness that LTE could do more for operators than just deliver more bits faster. At the very least, you might have something different to talk about for five minutes over coffee at LTE World Summit!
Keith Dyer is Editor of The Mobile Network, a title focussed on the development of mobile network technology. The next issue of The Mobile Network Quarterly will focus exclusively on LTE Progression. Go here to register to receive a copy.