MOBILE COMMUNICATIONS IN TWO UTILITIES

This paper was presented at the IBC TETRA Conference by the JRC Managing Director, Adrian Grilli. The conference was held on the 15-17 April 1996 at the Royal Lancaster Hotel, London.

INTRODUCTION

Utilities are Leviathans

Although concerned with the mundane supply of electricity, water, gas, etc., utilities are large organisations managing extensive networks with millions of customers, and information systems to match. The utilities may appear slow to take up new developments, but while it is often easy to develop demonstrators, the information capture processes to ensure that information is in the form in which it can be used by computer systems can require years of effort.

The business of designing, installing, operating and maintaining a network, be it gas or electricity is inherently geographically dispersed. The people doing the work are in the field, and it is not much use having all the latest in LAN networking, graphics workstations for the office staff if those operating the utility networks are excluded.

The approach

Some problems in IT take longer to overcome than others. While computer processing power doubles every two years or so, the increase in capability of mobile communications is slower in its evolution and even slower in its implementation - not surprising when the capital cost of many tens of millions of pounds is recognised. When unconstrained by communications restraints, computing techniques are delivering dramatically improved systems. The office based environment has a burgeoning range of information manipulation and access tools. But considered from the perspective of business need, there is a requirement to use information in those very places where communications are restricted. In comparison to line (or fibre) transmission rates and capacities, mobile communications will always have greater restraints. But currently the capability of PMR networks to support IT traffic is meagre. Current communications Currently, both utilities have essentially regional trunked private mobile radio systems based on MPT1327. The PMR system is fully integrated into the telecommunications network such that the mobile radio terminal is effectively an extension on the PABX (albeit with some severe restrictions).

BUSINESS REQUIREMENTS

While it is possible, and possibly fairly easy, to look at what facilities might be introduced over the current PMR voice and data capability, the long term strategic planning in the utilities demands that it be approached from a business perspective. What mobile communications facilities and capacity are likely to be needed in the future? It is this approach which is considered relevant to this conference.

The driving force has to be what the business will need in the future, but that is not easy to determine - certainly not a question to which an instant answer can be expected. Indeed it is a subject in itself, to bring together the business, organisational and technical issues and effectively redesign the organisation. While the sequence of events often follows what technology can do, it is possible to consider business objectives and the organisation structures to meet those and then define the technology needed to support that solution. Socio-technical systems theory has been used by at least one organisation in the electricity industry to explore what future technology is likely to be needed. In brief this approach attempts to look at the whole system, both technical and social, and to envisage how different approaches to each could result in business process improvements.

Within these overall methodological approaches there has been an ongoing process of analysis in a number of the electricity companies to build up an understanding of the tasks, and probably more expressively, the responsibilities, so that we have an overall picture of the business and can postulate different ways in which work may be undertaken with different technical systems. But it is important to remember that the communications network must support the business structure, not dictate it. The gas industry is currently in transition from 12 semi-autonomous integrated businesses into 5 product divisions serving two principal customers - the retail gas servicing organisation and the pipeline company TRANSCO. The radio networks are having to be reconfigured to support this new structure.

INFORMATION TO BE CONVEYED

One of the key issues is providing information into the field. At the simplest level, which is still quite complex, is the job despatch style of information which is being migrated to data in British Gas after many years of development of interfaces and protocols. Measurements indicate that whereas passing call details by voice requires typically between 40 and 80 seconds, the same information can be conveyed more effectively in data burst of less than 10 seconds over the same network.

Data systems are also seen to have value in the electricity supply industry, but there has been hesitancy in moving to these, partially because electricity networks pose operational challenges which suggest more complex requirements.

One of the broad issues which can be drawn out in the electricity business is the balance between centralised and distributed organisation. When there is a single network representation the 'technology' - ie the "wall diagram" limits the organisational solution to the centralised option. If the representation can be made available where ever it is needed, then the business has the option of centralisation or decentralisation or some mixture. In organisational terms this can be illustrated by the contrast with the centralised organisation with the engineer in charge in the control room despatching tasks to field operators, and the situation where the engineer can be in the field to see the immediate problem, but able to access all information necessary to see the overall picture. If the current network state is available in the field, the options of skilled staff at the centre instructing less skilled field staff, can be compared with the skill being in the field and the co-ordination role at the centre on not control. The business has to work out the myriad implications of organising work in this range of ways, taking account the wide range of work situations which arise. These range from the pre-planned work to the emergency situation where the numbers of staff in the field increases considerably. From the high level view of possible different processes the more detailed issues of the possible balances of skills and information flows can be developed.

CURRENT WAYS OF WORKING

In electricity distribution there are four principle networks, 132kV, 33kV, 11kV and Low Voltage, with the density of the network increasing with decreasing voltage. For consideration of power system issues, stability, connectivity and fault diagnosis the schematic representation is used, while a geographic representation is better for relating the network to customers and when physical access is required. Companies are part way through the massive task of producing computer based versions of these representations, and the amount of data involved for just one company runs into Terabytes. Likewise, the gas industry operates a hierarchy of high pressure gas distribution pipeline subject to the same requirements of security, integrity and control.

With the large volumes of data involved in the network representations, together with much other information relevant to work out of the office, such as plant details, customer data, it is an obvious approach to carry as much of the information with the field operative as practical. What is needed then is the software tools to merge locally held archive data with change information obtained by reference to the master version, so that the end user sees up to the minute information, without awareness of the mix of local and remote retrieval.

Both speech communication and information access are needed. Indeed the range of uses for communications in the field are likely to be considerably richer than current applications such as job despatch might suggest. One of the main conclusions is that there will be a requirement for simultaneous voice and data to support discussion of a topic between two or more separately located people while they share access to a common network representation. As an illustration of the sort of work which might need to be supported is the diagnosis of a fault and the steps necessary to restore supply. While for planned work on the network schedules are prepared for the switching and making safe of the network according to very detailed safety regulations, the fault rectification requires engineers to collaboratively identify the location of a fault, and then based on central and local information to make decisions on how the network can be re configured to restore supply to the maximum number, if not all customers. To do this people at separate locations need access to the same network representation, they need to be able to discuss possible diagnosis, which requires reference to the schematic, possible to plant records, but certainly they need to see they same diagram at both locations and to able to use normal discourse to arrive at a conclusion. Because of the safety to life implications the detailed safety rules need to be complied with, and the use of based systems becomes appropriate. While much of the bulk transfer of data to provide the shared schematic access might be obviated by local storage, there is likely to speed demands on the responsiveness of the system.

It is also clear that the envisaged simultaneous voice and shared information access would only be reasonable in the context of full duplex communication.

KEY ISSUES FOR THE FUTURE

The key issues are the anticipated timing of the introduction of such facilities and what mobile communications technology will be available. Will the overall level of traffic increase due to this more complex communications? Or will the gains in work effectiveness reduce the number of staff needed to manage the supply network and thus reduce the capacity required (unlikely but always possible)? Leading from that is the more technical question of the spectral efficiency of the mobile communications technique and whether the traffic can be carried within the available spectrum. Can this changed traffic be carried in the spectrum which is currently used and which is well suited to the nation-wide communications requirements into the variety of urban, rural and remote locations.

TETRA answers some of these challenges, but are applications going to need data rates of 10s kb/s and significant numbers of channels. TETRA can offer its 4x4.8kbs but only at the cost of using 25kHz of bandwidth. Will the needs of the utilities best be served by channels of moderately high capacity, supporting voice and data? One line of thought had suggested further subdivision of channels, either in terms of 5kHz channels or in the TDM structure of TETRA, but perhaps the need will be for a basic channel of higher capacity, say 30+ kb/s in a 12.5kHz channel.

The gas and electricity industries have relatively new trunked PMR systems and the path forward must maximise the exploitation of those systems, yet not hold back the business improvements which are likely to come about through using more advanced communications. Account also has to be taken of how longer term developments in mobile communications technology will meet the developing demands of the industry and how European spectrum rationalisation will dictate what frequency bands might be available by around 2008.

The utilities are faced with resolution of a number of complex issues:

1. the anticipation of organisational change and the prediction of the types and mix of services needed in 5, 10, and 15 years time.
   
   
2. the elaboration of mobile communication needs into channel data rates, and overall system capabilities.
   
   
3. the matching of these predicted needs with the mobile communications technology solutions which are likely to be available in the range of timescales.
   
   
4. the negotiation, both with other utilities to form a united front, and with national and international spectrum administrators to ensure spectrum availability for the projected services.

CONCLUSIONS

Does TETRA offer enough at the right time, especially in the context of the systems currently used and with respect to systems which might be available as result of current research? The utilities have more work to do determining what their future needs are, but work to date suggests that greater capacities will be needed, and in the light of spectrum pressure, techniques with higher spectral efficiency will be required. As the utility needs are clarified, in terms of facilities, capacity and timing, the ability of TETRA as against future developments will become clear.

Adrian Grilli, JRC Ltd, 26 March 1996.