The U.K. Office of Communications should act to...

tackled by outdoor solutions in which users receive a mobile signal from a network outside the building, or via indoor solutions where the signal comes from some kind of access point in the building dedicated to serving only that premises, it said. In the U.K., existing indoor cellular coverage provided by outdoor macro-cellular networks is at a high level for voice and data services, but the outdoor approach has some drawbacks, the report said. Among other things, construction material variations and building geometries may make it impossible for signals to penetrate inside all buildings, and trends toward more thermal shielding required in building regulations will significantly affect coverage levels over time, it said. So while outside solutions will continue to provide a baseline level of indoor coverage, there will be greater need for dedicated in-building plans to give consumers better services, it said. Poor indoor service arises from users being long distances from their operators’ sites; inside a building with challenging construction materials or layout; or in a high-rise that suffers from interference from multiple cells, the report said. Wi-Fi installed by an end user is a popular option for boosting indoor mobile services, but has been limited to data services unless the user wants to use over-the-top alternatives to voice and messaging such as Skype, it said. Carrier Wi-Fi, where operators are involved in deploying and managing the network and which allows roaming between their cellular and carrier Wi-Fi networks, is under development, it said. Traditional consumer repeaters and signal boosters are available in Britain but can’t legally be deployed without operator permission due to possible interference, it said. New, intelligent repeaters are helping to tackle those interference issues, it said, but they are not widely available. Femtocells have been rolled out commercially by all U.K. mobile operators and targeted to particular groups of consumers, it said. Picocells, which cover large areas, target larger small and mid-sized buildings. Distributed antenna systems, an infrastructure of cables, amplifiers and antennas installed inside to distribute mobile signals in analog form, are expensive to plan and install and are suitable only for large high-capacity or corporate buildings, it said. Hybrid solutions using femtocells, picocells and Wi-Fi are also promising, it said. The study looked at areas of concern for Ofcom in in-building solutions. These included: (1) Fully integrating small cell solutions into existing networks. (2) Ensuring that security best practices are set in consumer-accessible small cells. (3) The lack of a centralized security certificates authority to authenticate the identity of small cells, which could lead to a limited supply of vendors and access point products for consumers to choose from. (4) The fact that many in-building solutions are still fairly immature and of limited availability. Among other things, the report recommended that Ofcom give consumers information and help to identify the most appropriate indoor solution, and consider making low-power, shared-access licensed spectrum available for indoor deployment. The regulator should also consider monitoring and reporting on indoor coverage levels across operators, and analyze the U.S. situation with consumer repeaters to see if it might work in Britain, the report said.