Cellular Mobile Communications Heritage

The following article appeared in I A News 174, Autumn 2015, but regrettably with not all its illustrations. These are correctly included here with apologies to Andy Sutton.

It’s just 30 years since the UK’s first commercial cellular (mobile) telephone network was launched. However, in this short time the industry has evolved at an extraordinary pace from basic mobile telephony to advanced mobile computing. The development of telecommunications is not as well covered as it should be from an industrial heritage perspective and mobile communications even less so.

The first network to be launched was Vodafone on 1 January 1985 with Cellnet following shortly afterwards. Artefacts which survive from the early days are the actual mobile phones: youngsters are often shocked by the size and weight of these and more so by the fact that you couldn’t sent text messages on them! The topic here is not the mobile phone itself but rather the infrastructure which powers the cellular networks and in particular cellular radio base stations. The speed at which the mobile industry deployed radio base stations was remarkable; at one point there were over 52,000 operational radio cell sites in the UK. The number has been reduced slightly recently as mobile network operators are increasingly sharing infrastructure. In just 30 years the physical form of a cellular radio site has changed significantly. Quite often this goes unnoticed as the radio tower, column or rooftop installation is still there, yet the evolution from first generation analogue systems to 2G, 3G and now 4G digital systems has changed the radio antenna systems and site equipment considerably.

The actual structures on which the antenna systems are mounted vary considerably and for a variety of reasons; from planning permission to site provider requirements and from radio planning considerations to structural loading. Structures can be classed as masts, towers, columns, street-works (lampposts) and many other things, including some even disguised as trees.

174 F4a Figure 1_TowersFigure 1: Cellular base station towers.

Figure 1 illustrates the diverse range of towers in use for the provision of cellular radio signals; on the left is a pre-cellular microwave radio tower which formed part of BT’s national telecommunications trunk transmission network before buried fibre optic cables were used. The tower in the centre is an early Orange radio site deployed in 1993. The dimensions of the top of this tower are quite specific as two antennas are separated by a certain distance and operated cooperatively to improve the received signal from the mobile phone, a technique known as space diversity. The tower on the right illustrates a new technique. Rather than space diversity, an alternative known as polarisation diversity is employed; this removes the need for the spatial separation of antennas and allows for narrower structures.

174 F4b Figure 2_StructuresFigure 2: Column, lamppost and rooftop (with stub tower) installations.

Figure 2 shows a range of non-lattice tower structures, albeit the stub tower on the water tower rooftop is a short lattice tower. A circular dish-like antenna can be seen just below the long cellular antennas on the column on the left; this is a ‘point to point’ digital microwave radio system which provides the connection between the cell site and the mobile operator’s core network. Rooftop installations can take many different forms, from the stub tower seen on the right of figure 2 to simple poles and antennas often mounted on the side of a building, which minimises the impact on the skyline. There are many technical, commercial and planning reasons why a given cell site looks the way it does.

174 F4c Figure 3_Specials (1)Figure 3: Non-standard cellular installations.

There is a wide range of less obvious cellular installations in the UK; figure 3 highlights just three examples. Fake tree structures have been deployed across the UK, often in areas of outstanding natural beauty. The folly in the middle photograph was badly vandalised and attracted anti-social behaviour before the cellular installation; as part of the agreement with the site provider the mobile operator renovated the structure and fitted a secure door. On the right of figure 3 is a piece of community art with the cellular antennas integrated in the upper section.

We have already lost a significant amount of heritage as not a single first generation cellular site remains in existence in the UK and of great concern is the lack of photographic and documented evidence of this period, a period on which our future connected society is being built.

Andy Sutton

All photographs by the author.