The first of the new UK Band III private mobile communications services began operations this week to lead the next stage of the UK’s booming mobile communications market. The UK had the lowest penetration of mobile equipment per head of the population in Europe before 1985 according to the managing director of the new mobile communications company, called Band Three Radio Ltd. Now there are almost 17,000 licencees of private mobile radio systems and 24,000 radio base stations serving 450,000 mobiles in the UK. There are also some 230,000 cellular radio users. The biggest crimp on further growth is the capacity constraints that are inevitable with the limited spectrum availability. The Department of Trade and Industry is having to deal with the increasing problems created by the success story of mobile communications in the UK and has, therefore, been keen to get Band III on the road before the year was out. Unlike cellular radio, where the TACS specification, a modification of the US AMPS system, was already in place, the UK has had to write the specifications for Band III from scratch. And they show every sign of being taken up on an international basis, according to junior industry minister John Butcher. Consortium Band Three Radio Ltd is an operating company under a consortium holding company in which the share-holders are Philips, Securicor, Racal and Digital Mobile Radio, which own roughly 25% each. It is the first of the two UK parties, which were licensed by the Industry Department in 1985 to run a nationwide mobile radio service in the 175MHz to 225MHz spectrum, to get underway. GEC on its own is the other but it does not expect to launch its National One service until January 1988. GEC is holding out for compatibility with as many of the details of the specifications for Band III, defined by the givernment, as possible. None of the four specifications has yet been published because a patent dispute between Motorola and Philips has held things up. But the two companies settled their differences last week and the first two specifications have been more or less accepted by the operators and manufacturers. MPT 1327 is a generalised protocol, which covers in broad terms the basic signalling specification for the Band III networks. The remaining three re-late specifically to Band III. MPT 1343 governs the mobiles, how they respond to signals and how they roam onto other networks; MPT 1347 determines the characteristics of the network infrastructure; and MPT 1352 sets out how the equipment should be tested. The last two are not likely to be securely established until the first half of 1988. In order to get launched, Band Three has, with Department approval, defined an interim specification to state how mobiles should work, which will remain in force for any mobiles supplied for use on its network for five years following publication of MPT 1343, and enabling service providers to sell them for one year afterwards. GEC, however, wants to start with base stations that are MPT 1343-compatible. MPT 1343 also includes a nat-ional numbering plan so users will be able to link to British Telecom and Mercury’s public networks. Mobile manufacturer Storno of Camberley has promised GEC that it will have such a product ready in a matter of weeks, which will enable subscribers to use not only the GEC network but also the Band Three Radio network. The same will not be possible the other way round until Band Three Radio upgrades. GEC is also holding out for is an extension to MPT 1327, which will come early in 1988, that will enable Band III to cope with longer data messages, where it takes them in short bursts currently. This gives Band III an advantage over the cellular networks for sending data messages because the user does not need a modem to deal with data. Most existing mobile communications systems use a single channel method, where subscribers must take turns to share a single channel. If the line is engaged, then they must redial. Band Three Radio says MPT 1327 allocates a dedicated channel to each user. This is a techniqu
e called trunking and its advantage is that a greater number of users can be supported per channel. It is a method that pools radio channels so that when users wish to make a call, they can choose from a set of channels rather than a single channel. This automatically increases the chances of getting a channel. We can get 120 subscribers on one channel for normal two-way use, says managing director Andrew Robb. There is only access for around 25 subscribers to one of the cellular operators’ channels because their cells are so much smaller than ours. GEC aims to run its network as a value added network service. It will be based on System X exchanges using the C7 signalling standard to take voice traffic from the base stations, which act as local exchanges. A separate minicomputer, from GEC’s 4000 series, will then act as a packet switch for customer’s data. Band III is being aimed at the mobile communications market as a complementary service to cellular radio at the top end and paging at the bottom end. The two national nets will initially be quite different with Band Three Radio having the advantage of a head start and GEC starting with more technical sophistication. The main tabget for the service is the transport industry, fleet operators, any companies that have a requirement for a bulk of spectrum use for which they can calculate their costs in advance. Envy of Europe Users of the Band Three Radio service pay a monthly subscription fee of UKP20 in London and UKP15 in the pro-vinces for which they get unlimited use of the network. They do not pay call charges on top of that. The spectrum allocated for Band III was formerly used to broadcast black and white television signals and 100 channels each have been allocated to GEC and Band Three Radio Ltd with another 200 on standby. Band Three Radio is setting a limit according to that allocation of 60,000 subscribers, which it aims to reach within four years. Band Three Radio currently covers 20 UK regions, in-cluding the Thames Valley, the West Midlands, two Yorkshire areas, parts of the home counties and three London areas. It will cover 40 regions, about 60% of the UK by March 1988 and by 1991, 80% of the population should be within reach of the company’s coverage area. Users of the Band III service will feel some of the same benefits that cellular radio users enjoy given that they will eventually have a choice of two competing national networks as well as a choice of handsets and service providers from which to buy them. We’re likely to be the envy of the rest of Europe, says John Butcher. Managing director of Philips Radio Communications Systems Ian McKenzie says the UK is promoting MPT 1327 through telecom agencies in Europe and he expects to see some concrete standards being set for private mob ile communications like Band III on an international basis by spring.