Avren’s annual BaseStation conference was again highly insightful, covering both the macro economic factors affecting network operator’s businesses as well as the technical detail of the real world engineering  in use and under development today. The conference addresses the needs of European operators, with contributions from UK, Austria, France, Sweden  and elsewhere.

Mobile Network Economics

A talk on network economics might sound a dull title, but David Hazeldine of T-Mobile kept everyone’s attention by reminding us of the bigger picture. Operating a mobile network contributes around 30% to the annual costs of each operator, and there are many different ways to save money. Where before, coverage was a real differentiator between networks, today it’s much more about service. There are enormous savings to be made by sharing cellsites between operators – T-mobile and 3 in the UK have combined their cellsites and reduced the total number from 55,000 to 31,000 in the last two years. The number is now slowly expanding again to fill in coverage holes and add capacity. The recently announced merger between Orange UK and T-Mobile means a further round of site consolidation over the coming years. Meanwhile, their UK competitors O2 Telefonica and Vodafone have also made a site sharing agreement, meaning that there will be just two competing sets of cellsites across the country.

Ovum, another UK based consultancy, took the concept of radio network sharing a step further. Comparing it with utilities such as electricity, gas and water, they suggested that a single national infrastructure could be shared between all network operators. Each would effectively be an MVNO (Mobile Virtual Network Operator) and compete on service and customer care. An example was given of Sweden, which has agreed to build out a common, shared 4G network. I know of at least one other European company with similar plans. 

Some speakers questioned the sense of offering unlimited flat rate data plans – the industry sentiment is that these can’t last. The highest traffic users are consuming disproportionate amounts of network resources – several examples were given of 2 or 3% of users taking up over 40% of available capacity. Several European operators privately shared their views that HSPA+, the evolved 3G radio technology, closely matches the performance and capabilities of LTE, the new 4G technology. Spectral efficiency, latency and high speed data rates were said not to be that different – one speaker challenged the audience to say what new service LTE would enable that couldn’t be delivered with 3.5G – quite a controversial point.

There was a general theme at this European basestation conference that LTE would not be deployed in volume until perhaps 2013, and would primarily be used for extra capacity in urban areas. One exception, advanced by Motorola, was to provide broadband service in rural areas which have no wireline alternative.

Metro Femto

Kenny Graham, Vodafone R&D Group, has been a keen champion of femtocells in public areas for some time – coining the term metro-femto. He believes that the most difficult challenges for femtocell deployment have already been overcome. He classified femtocells into four groups and clearly believes all have a place in network deployment:

• Domestic
• Enterprise
• Public service areas (indoor hotspots)
• Metro Femto (Outdoor hotspot )

Installing more antenna and equipment at existing cellsites, such as required for LTE or MIMO technologies, is constrained by physical and planning limits of cellsites. Metro femto can be deployed unobstrusively in the urban areas with peak traffic demand, providing high levels of capacity.

Low cost satellite connections for remote areas

At the other end of the spectrum (in more ways than one), Avanti presented a solution for remote, rural deadspots that are still unconnected. Avanti is a new satellite operator with some $500 million in the bank  launching two new satellites covering Europe, Middle East and Africa. These can provide a connection anywhere in their coverage area using two way terminals costing around  $500. Among other applications, it was suggested these could be used to provide backhaul for rural femtocells, lighting up small villages with 3G coverage where other methods aren’t available or commercial viable.

Femtocell Seminar

Chris Cox of ip.access gave an excellent seminar on femtocells, reinforcing the arguments for them. He ran through the various technical hurdles which have been overcome, and pointed to several Femto Forum publications for further reading.

Some (new to me) factoids came out (I must point out these are not specific ip.access issues!)

• Some countries demand a fee for each new cellsite deployed. This has had to be changed for femtocells to make them viable.
• Russia required a permit before each basestation could be installed, which took about 3 months to process. This requirement has been withdrawn for femtocells.
• Some countries have particularly poor uplink rates on their ADSL broadband lines (compared to others). This limits the concurrent voice call capacity of the femtocell (which needs to be smart enough to adapt).
• Some early femtocells had a lot of “chatter” with the network, eating into the wireline broadband allowance; this has since been optimised

And Finally

Femtocells still seem to me to be a quite separate discipline from mainstream cellsite basestations, but there is growing awareness. There were few technical presentations that spanned across both. However, the fact that femtocells now form a significant part of the agenda as well as the exhibitors, plus the interest shown by those at the Femtocell Seminar suggest that this might change in the future.

I’ve found Avren’s conferences are always well produced and attract many high quality speakers and attendees actively involved in the technical operation and strategy of mobile networks. Given that the event was scheduled for the same week as all air traffic in the UK was grounded due to Volcanic Ash, Avren rose to the challenge and held the event with a few speakers presenting and several attendees viewing remotely by video link. A triumph over adversity to say the least.

Their next major event will be the Femtocell World Summit in London (June 21-24th). With over 300 delegates at last years jamboree, it's the most important single conference in the femtocell industry by far. This year's promises to be an outstanding event - don't miss it.