Original URL: http://www.theregister.co.uk/2009/06/26/in_building_mobile_coverage/

In-building coverage: What’s the problem?

Signal suckers

By Josie Sephton

Posted in Mobile, 26th June 2009 11:13 GMT

Most mobile calls, voice and data, are made inside a building – at home, at work, in the shops. Although the issue of adequate coverage in business premises has not been critical up to now, this is increasingly more than just a nagging concern for many organisations. In some cases, such as emergency services, good in-building coverage is essential.

Users expect that coverage is of consistent quality, with adequate capacity. But they are often disappointed. Building materials can significantly affect signal strength. In particular, more energy-efficient, heavily insulated buildings can be real signal-suckers.

Also, interference from electronic equipment, conflicting signals from multiple ‘macrocells’, as well as capacity limitations in high user density locations have an impact. This problem will grow, as higher frequencies emerge for new data-rich applications, and as user demands around video and data services increase.

The ultimate suffering party is the end user, but isn’t this a problem for the mobile operator? Up to a point. If they can provide better in-building coverage, they are more likely to attract and retain customers. They will also benefit from increased usage, and in turn, revenues – ability of use being more likely to lead to increased use.

Call the operator

But in reality, the chances that operators will solve every in-building coverage issue are very slim. The chances of them doing in the timescales required by many enterprises are even slimmer. And so, the problem becomes one that the enterprise may well need to address, in part – e.g. joint funded with an operator – or by themselves. This is especially pertinent when organisations are seeking widespread wireless implementation. Where the enterprise need to spend money, due care is key when deciding the infrastructure, including future proofing. It is wise to engage with your operator as soon as possible.

A likely outcome – as is often the case with various aspects of comms - is one which incorporates several, complementary technologies. Wi-Fi may provide a solution in part, but limitations may include handset restrictions and investment (particularly if seamless cellular/Wi-Fi/cellular handover is required). In addition, a glut of usage could easily overload the network – and this isn’t what Wi-Fi is really about. Femtocells - small cellular base stations typically designed for use in residential or small business environments - are best suited for hot -spot or small -venue voice. Similarly, pico cells are more appropriate for smaller buildings and small and medium-sized businesses.

The increasingly popular Distributed Antenna System (DAS) may be a more appropriate solution for larger enterprises/locations and for achieving high speed data transfer rates. This provides efficient distribution of wireless connections inside large buildings, by routing radio frequency signals through fibre or copper cable from a single base station to multiple antennas located throughout the building. DASes are also more easily managed as components in a wireless network.

Detailed planning is essential, irrespective of the group of technologies selected. Consideration needs to be given to support of multiple standards, and mixing fixed and wireless infrastructures. The extent and capacity of wireless throughout the building, and management of the systems also needs to be factored in, as does future-proofing. In an increasingly wireless working environment, risk and concern around radio frequency (RF) emissions will also need taking into account.

When working with the mobile operator, an unambiguous definition of management responsibilities will be essential. This will ensure clear lines of responsibility when any issues are identified, especially in any "grey" scenarios. Finally, rules around connecting with multiple mobile operators will also need to be dealt with.

It is beyond the scope of this article to do little more than identify some key considerations. but our most important point is that in-building coverage will progress from nagging concern to serious headache, as businesses become increasingly serious about deploying wireless applications originating from the cellular camp. Successful deployment of wireless will require this to be tackled head on, preferably arm-in-arm with a mobile provider.

We are interested in hearing the issues you have faced with in-building coverage, and how you’ve moved things forward.