STAFFORDSHIRE POLICE LOOK TO ATDI FOR CONSULTANCY IN AIRWAVE PROJECT

Police in Staffordshire are enjoying better confidence in the performance of their Airwave service after calling in the consultancy services of ATDI to help establish their coverage requirements.

The Staffordshire force wanted to verify its own preparatory work for the new service to make sure that incidental coverage would be sufficient for its operations. The reliance on incidental coverage followed its decision to take a considered or value based approach instead of simply requesting blanket coverage of the country from O₂, the Airwave Network provider. 

Proposals from O₂ based on these coverage requirements had to be analysed and the impact of factors such as portable wearing options, multi-slot data usage, and the use of gateway repeaters had to be reviewed.  The aim was to assure officers on the beat that they would receive an adequate radio service whilst keeping the annual service rental cost within reasonable bounds.

Staffordshire Police decided to contract the project out to ATDI, which has worked with other police forces on similar tasks.  ATDI’s first step was to audit the methods used by the Staffordshire Police Airwave team, which had translated users’ needs into technical specifications required by O₂.  Next, work progressed to analyse the actual coverage requirements and equipment criteria to produce a design standard.  This was then used to develop a hypothetical reference network designed to provide county-wide coverage.

This hypothetical network provided a statistically valid representation of the real network to be provided by O₂.  It could be used to infer the effects of all the variables likely to affect the police service during the network’s life.  Since the location of portable radios on the body affects signal capture and hence coverage, wearing options were detailed and applied to the hypothetical network to demonstrate how coverage would be affected. 

Similarly, building-penetration losses were determined for various types of building, according to international standard references.  The police team could then compare these in-building predictions with their requirements and could make appropriate changes to their order for additional coverage from O₂.

In addition, using the hypothetical reference network, ATDI was able to determine the network’s ability to meet the letter of the PITO (Police Information Technology Organisation) specification, and to compare its findings with the O₂ proposals.  It transpired that there was a real need for gateway repeaters to support the force’s intended reliance on incidental coverage. 

Commenting on the project, Inspector Grahame Craddock, project manager for Staffordshire Police, said:  “ATDI has delivered a comprehensive report to us that clearly specifies where we need to make changes and why.  We are confident that all possible scenarios have been considered and, as a result, there is a much higher probability of the Airwave network giving us the right level of coverage across the county.  This is essential for us to continue to serve the community of Staffordshire successfully.” 

BETTER COMMUNICATIONS FOR IMPROVED LONDON BUS NETWORK

A recent technical review of London's bus radio, automatic vehicle location and Countdown passenger information system has highlighted that whilst the system is fudamentally sound, its performance needs to be improved to meet a changing requirement specification. London currently has the largest real-time AVL and passenger information system in the world and London Buses is committed to investing in further improvements to deliver passenger benefits across the expanding network beyond the 7000 buses currently operational.

To be able to achieve some of these expansion aims, London Buses has to make a number of changes to its existing radio system which uses MPT1327 radio technology. This does not automatically dictate a system replacement and it is ATDI's job to assess the current situation and recommend possible courses of action. If the existing system can be enhanced and optimised to provide for the growth objectives of London Buses then the system will remain in operation longer than originally planned.

London Buses called in ATDI to carry out a comprehensive analysis of its existing radio system. The purpose was to deliver a set of recommendations for optimising the system or replacing it with a more modern digital alternative or new MPT1327 system. London Buses would need to explore each option.

The original system was designed in 1987. Since that time, considerable investment has been made in the system to provide for more voice and data traffic and AVL system data, but it is evident that coverage varies across different areas/bus routes. The modelling carried out by ATDI is intended to show what percentage of the routes are covered today by the radio system. From this information, a picture could be developed to show how radio sites could be repositioned or established to deliver improved coverage across the city. The channel capacity at each site could also be modelled ensuring the operators have a sufficient grade of service.

The ensuing report picked out specific areas of concern, both geographically and technically. The report outlined the improvements to be made and detailed the infrastructure enhancements required. The aim was to re-design the network to achieve both coverage and resource balance. Having carried out such intensive analysis of the network during the initial phase of the project, the data in ATDI's possession was comprehensive. Theoretically this would make network optimisation largely straightforward.

ATDI's ICS Telecom was used throughout the project to provide detailed calculations on coverage, capacity and spectrum interference, and to deliver the necessary information from which to make relevant recommendations. ”

Dave Mastin, Technical Manager at Communications Systems, London Buses, said "We are committed to enhancing our services and technology plays an important part in this. ATDI has carried out the initial phase of the project and we are now analysing the findings and recommendations in preparation for the implementaion phase. This needs to take into account possible substantial increases in the size of the bus fleets and we shall use the study to support our applications for additional channels to the Radiocommunications Agency. We are impressed with the capabilities of ICS Telecom and we are confident that the modified radio network will help to provide the way forward for London Buses to support the Operators, and to help us to continue with our roll out of the Countdown system of real time information at bus stops."

TETRA - A TECHNOLOGY LOOKING FOR A MARKET?

The TETRA World Congress in Nice set the scene for our joint presentation with Aerial Facilities entitled “Delivering TETRA Service to Key Users in Key Locations”.

The conference itself focused on the question of whether TETRA is delivering the benefits intended of it.  For example, some would believe that there is a risk of it becoming a technology that is looking for a market, after all, we are already in the second generation of the TETRA standard and release one has yet to see wide spread realisation. 

In the workshop, ATDI and Aerial Facilities illustrated that TETRA is remarkably mature.  With ATDI’s extensive association with the Airwave project in the UK and as architects and consultants in other regional and national networks across Europe, the process of detailed planning in coverage, traffic and interference is very well proven.  The workshop struck a very practical tone imparting technical detail whilst avoiding the sales spin so common in such events.

ATDI demonstrated to the audience how to design for the provision of coverage to TETRA users in the street and then developed this logically to users in buildings.  They explained how to model degradation of performance as users move within buildings of different types and demonstrated how to maintain availability in the presence of signals described by multiple probability distributions.  It was a highly technical and comprehensive presentation which mirrored the business of both presenting organisations and was greatly appreciated by all who attended.

Using their planning tool, ATDI graphically demonstrated what happens when users go deep indoors.  Signals become victim to excessive penetration loss.  High-needs users then require internal infrastructures to maintain median signal levels at contracted levels.

Aerial Facilities took over from here by explaining how to capture a signal from outside, amplify it and distribute it within the building so that the coverage specification can be met across the operating area -  in-building and out.  This technology is vital where service is needed in large public buildings such as shopping centres and for locations like London Underground where coverage must be provided below ground.

The workshop was a great success.  The audience was taken on a journey from conventional planning for service in the street to indoors,  then to deep indoors and shown how to overcome the numerous problems along the way.

THE PROBLEMS WITH BROADBAND WIRELESS ACCESS (BWA)

The idea of competing with wireline and fibre was compelling, but BWA has not yet established a strong hold in the market.  Even changing the business model to include BWA as a flexible access method in a mixed wire and fibre telecoms offering has seen limited success. The problem seems to be that few perceive the ability to make enough money from it. 

Recently the technology has split into two distinct areas:  point to multi-point and wireless LAN.  Traditional point-to-multipoint BWA continues to be developed and this now includes mesh networks which are simply a variation on the theme.  Wireless LANs and IEEE 8.02 standards combine to make use of the release of spectrum in the 5GHz area.  Use of these wireless LANs, or WLANs, are stimulating broadband provision, providing ‘BWA on the move’.  This allows users of the service to download emails whilst away from the office and unable to establish a wire connection.  One of the most obvious applications of this is within airports where business users are given access to their corporate IT systems while they wait for their flight.  The commercial benefits of such a service are clear. 

Flexible licensing will play a major role in the acceptance and implementation of such BWA services.  There are regulators that have recognised that network operators are unlikely to buy large tracts of spectrum or to install national networks.  A localised service is more compelling and providers may be more prepared to invest in the provisioning of such a low risk, low entry cost service erecting a small number of base stations to test the market. 

This approach is a short-term solution to the problem, but it may well generate problems of its own in the longer term once the market has been stimulated and mass deployment begins. 

ATDI is active with ComReg, the Irish Regulator, in developing spectrum regulation to ensure that small numbers of base stations can operate without interference whilst not precluding subsequent growth.  The Irish regulator has taken a very pragmatic approach to allow the business to get started and to deliver to the market what is required to assure this. 

“I believe that other European administrations should learn from this innovation when developing their licensing approaches if BWA is to turn the corner and gain greater acceptance.  Operators should not expect access to great tranches of spectrum until their business case is proven: Conversely, they should not have onerous license conditions forced on them demanding questionable wide area deployment.  I believe that a local, smaller scale approach certainly has merits in the current climate” said John Berry, Managing Director at ATDI.  “Of course, there are technical problems to be overcome but these are good problems to have when at least there is a market” he continued.

There is a great deal of interest in BWA technology (in all its guises) for use in access provision and this was confirmed by the high attendance of the BWA Conference in Cambridge, UK, in late November 2002.  What is needed now is a number of competitive deliverable service offerings from a variety of operators to stimulate further market growth.

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