Qualcomm has partners, journalists and analysts in Berlin for its IQ event. There are a number of network-related demos, featuring LTE-A, LTE Broadcast, femtocells and UMTS Direct demos. I've briefly summarised a few of them here.
Fractional UMTS
The first one I saw was on Fractional UMTS – F-UMTS – a method of squeezing UMTS into half of a "normal" 5MHz channel, by reducing the baseband chip rate (Mcps).
Qualcomm said that delivering UMTS in half the available channel, allows operators to roll out UMTS where they are spectrum constrained. Essentially, F-UMTS delivers UMTS over half the channel bandwidth normally used, meaning operators can deliver UMTS over 2.5MHz channels – accepting that throughput will be half that of a full channel deployment. So, if you have a 14.4Mbps capable base station and device, you're going to get a max of 7Mpbs using F-UMTS.
Qualcomm demonstrated two femtocell reference platforms, one at 5MHx channel bandwidth delivering 7.2Mbps and one operating over a 2.5MHz channel tdelivering data at 3.6Mbps, to two handsets. The two handsets, were streaming the same content, with little observable difference between the two.
What’s the advantage? Well, for carriers that are spectrum constrained, or have non-contiguous spectrum that means they can’t upgrade in 5Mhz chunks, Qualcomm says F-UMTS can help deploy UMTS where there is constrained spectrum. Also, it might allow operators to refarm small chunks of 2G spectrum, enabling them to keep the majority of spectrum for 2G. There’s also a small cell application, allowing an operator to use a dedicated channel for femtocells, but again conserving more channel space for the macro layer.
What is required? A software upgrade to the device (all OK for the Snapdragon platform), and to the UMTS base station, as well as to the RNC.
Neighbourhood open mode femtocell concept
This was a demo of a model of residential femtocells working in public access mode. The vendor claims that with just 5% penetration of femtocells, in a given area deployed on a dedicated carrier, all users can achieve a 13 times increase in throughput by benefitting from a less busy macrocell and from other open femtocells as they move around a location.
So although the model requires a dedicated carrier for the femtos, Qualcomm said that even at quite a low penetration rate, operators can benefit from switching femtocells to open access mode. Of course, open access femtocells providing overlapping coverage that is intended to hand off users from cell to cell requires a fair amount of mobility management and interference management. Qualcomm said it is working on a range of SON techniques that it will make available with its small cell reference platforms for OEMs, including items such as self configuration and calibration, range tuning, controlled limit on UE power, macro aware rise settings, active hand-in, beacon based femto discovery, transmit and receive diversity.
Qualcomm has installed 7 femtocells in indoor locations in its San Diego campus. It says that is enough to have given it coverage across much of the campus. Users moving around the site have full mobility, with hand-offs between cell locations.
Certainly small cells are now a key priority area for development within Qualcomm. During his keynote, COO Steve Mollenkopf said, “For further capacity improvements we really think the opportunity exists to make many, many small cells and really diversify the deployment scenario in the network.”
A mass deployment of small cells would bring R&D challenges with it, he added. “There’s still a lot of innovation needed, for very low cost cell sites, the backhaul problem, interference management, and on the device side to offload onto he right network at the right time. There’s a lot of innovation to happen, but that’s a big priority in our 10 year vision for company,” he added. Indeed, Qualcomm took a leaf out of one or two NEP playbooks by flashing up the legend, “Small Cells Everywhere” over one of its slides.
LTE Broadcast
Qualcomm has taken many of the assets from its doomed MediaFLO products and programmes, and rolled them into a renewed mobile broadcast offering for LTE using the eMBMS standard.
This demo modelled how an operator could use LTE capacity reserved specifically for eMBMS to deliver broadcast content in certain locations at certain times. Qualcomm demoed two use cases. One was a stadium, where there may be thousands of users interested in viewing the same content. By reserving 30% of available LTE capacity for eMBMS an operator could delive seven channels of broadcast video at 800kbps, Qualcomm said. A unicast service trying to deliver the same content to a similar number of users would fall over with just 2,300 users in the stadium, the demo claimed.
Another use case for LTE cell broadcast is file delivery (Video on Demand uploads) or firmware updates at downtime and non-peak hours. After midnight, an operator could spend an hour or two broadcasting content or updates to devices.
What is required? eMBMS needs to be made active in the LTE chip. Qualcomm said it would have LTE chips with eMBMS available by the end of 2012. The operator obviously needs eMBMS enabled as a software upgrade to the EnodeB (Qualcomm demo'd this with Ericsson at MWC 2012 and is working with other NEPs) and also a Broadcast Multicast Service Centre.
LTE-A
Qualcomm has a live LTE HetNet up and running in San Diego. It is using that deployment to demonstrate some features specified in 3GPP R10 and R11 (LTE-A), such as advanced interference management and the ability to allocate radio resources in an adaptive manner.
Some of the features included here are adaptive network partitioning, range expansion and interference cancellation, using eICIC.
The demo shows how resources could be applied dynamically to a picocell that has more users on it at a given time, with the intelligent base station allocating more subframes to that picocell. When these users move outside that picocell area, and the macro sees more demand, then the macro area network is then re-allocated those sub-frames.
These sorts of solutions, designed with the co-ordinated HetNet in mind, are going to be explored in more detail in Mobile Europe’s next Insight Report, which takes a close look at LTE-A standards and recent technical advances.
LTE Direct
This is a vision of an extension of the UMTS standard that would allows users to discover when they are near to devices belonging to people they know. The idea is that devices would broadcast and receive small signal messages (128k) sent in a reserved timeslot every few seconds. These messages would enable devices to advertise their location and discover other local devices without using location technologies such as GPS or WiFi localisation. It is also designed to be light on the signalling network, Qualcomm said, with the capability integrated down in the modem.
The inevitable use case we saw was in a shopping mall. User A “discovers” User B is near them in the mall, they meet and have a coffee, or whatever. There was some brand couponing, offers, social media integration type of stuff. You probably get the picture.