Wireless The answer to all our communications needs?

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Evan Bailey
8 years ago
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1 Wireless The answer to all our communications needs? Introduction Since BT s last review of its leased lines back in 2003, there has been a concern in local government that analogue lines will go the way of the dinosaurs, the dodo, and good English tennis players. Converting all analogue lines to digital is not only costly to implement, it will also be very expensive to run. This, along with the requirement by the Government for all on-street applications to be centrally managed, is making councils look at other forms of communication for these products. Wireless, with its relatively low cost to install, and with very little on-going revenue cost, seems to be the answer to all our prayers. But is it as easy as that? We ll look at solutions available to the council today; compare the pro s and con s of the available technologies, see what s already been implemented, and see if Wireless really is as good as it seems. Why look at communications? There is a need to provide information from the street back to the central management and control of city applications. This is taken from the UTMC Website:- To assist local authorities gain the most from ITS and achieve their transport objectives, the UK Department for Transport initiated the six-year, 6M Urban Traffic Management and Control (UTMC) programme in The first half of the UTMC programme ( ) concentrated on specific applied research tasks, on both technical and operational issues. UTMC systems are designed to allow the different applications used within modern traffic management systems to communicate and share information with each other. Thereby a more robust and intelligent system can be used to meet current and future management requirements What s wrong with what I ve got? Traditional communication systems for on-street communications, such as traffic light controllers are analogue, i.e. BT copper line circuits such as EPS 9. More and more on-street applications require a digital connection back to the server that is managing them at the in-station. There are two main problems with this. Firstly, BT are already introducing digital lines across the UK, BT s 21st Century Network (21CN). Secondly, the cost of fixed-line communications will increase moving from analogue lines to digital lines, both on an ongoing revenue cost, and an installation cost through digging up the road.

tennis players. Converting all analogue lines to digital is not only costly to implement, it will also be very expensive to run.

2 The solution Wireless? Wireless communications seems to solve a lot of the issues caused by the country-wide move from analogue to digital. It allows the council to implement a city-wide digital network and thus communication to centrally managed on-street applications, whilst keeping down the on-going revenue costs of fixed lines. Capital costs for installation are also reduced, as there are very little civil costs involved. There are, however, a number of different technologies available. Wireless Technologies There are a number of wireless technologies available today:- Zigbee: low-power digital radios based on IEEE short distance Ultra Wideband (UWB): a technology for transmitting data spread over a large bandwidth (>500 MHz) short distance Bluetooth: operates in the unlicensed ISM band at 2.4GHz short distance Wi-Fi : family of specifications developed by the IEEE for wireless LAN technology WiMAX: based on the IEEE standard long distance Proprietary Wireless, i.e. Mesh4G : wireless solutions developed for a specific purpose There are also a number of frequencies available, however the two main ones that are unlicensed, i.e. there is no on-going cost to use them, are 2.4GHz and 5GHz. 2.4GHz Standard frequency for hotspot Wi-Fi communications Pass through several walls Limited to 100mW of power Range between 10m 1km depending on technology Bandwidth between 2Mb 16Mb 5GHz Standard frequency for CCTV and office to office wireless bridges Cannot pass through walls, i.e. a line-of-sight solution 5.4GHz is limited to 1W, and 5.8GHz is limited to 4W of power Range between 50m 100km depending on technology Bandwidth between 12Mb 300Mb We will look at the most appropriate technologies, , and Mesh4G (proprietary).

Capital costs for installation are also reduced, as there are very little civil costs involved. There are, however, a number of different technologies available.

3 Why Proprietary Wireless? Comparing standard wireless technologies, and Mesh4G wireless, we can see why only Mesh4G is acceptable for real time on-street communications Mesh4G Open Protocol is susceptible Propriety Protocol cannot be seen by anyone that to hacking, insecure is not on the network Limited transmission Transmits further distances at same power level as distances (up to 150m) due to more sophisticated transmitters & Designed for Indoor use not suitable for street environments Susceptible to interference only uses 1 non-overlapping channel at a time Polite Protocol listens and waits until channel clear before transmitting data receivers (up to 1000m) Designed for wide area, mobile ad-hoc network applications Not limited to 1 channel - listens across the 4 nonoverlapping channels and transmits on one with least interference Does not use Polite Protocol does not wait sends data all the time ideal for Real Time Information Other Benefits of Mesh4G Mesh4G uses an advanced radio originally developed for the US Military with $350m funding. It uses Direct Sequence Spread Spectrum (DSSS) and operates in the ISM II 2.4GHz bands. Its structure enables dynamic, packet-by-packet routing on different frequencies and routes. Mesh4G is a robust, self-forming and self-healing technology that is resilient to interference. It allows central control and management of city applications whilst reducing civil engineering and ongoing revenue costs for leased lines. Networks are scalable up to 100,000 nodes.

11 Mesh4G Open Protocol is susceptible Propriety Protocol cannot be seen by anyone that to hacking, insecure is not on the network Limited transmission Transmits further distances at same power level

4 Implementation When installing a city-wide wireless network, the idea is to work from the ground level upwards. Using all existing networks that you have, i.e. copper, fibre, WAN, and then expand from there out on to the street. On-street applications that require real-time communications, such as traffic light controllers should use 2.4GHz Mesh4G radios, installed at 3m height for ease of installation, as the signal will be able to pass through any vehicles that could stop next to a radio. CCTV or other applications that require high bandwidth should use 5GHz Mesh4G radios, installed at 10m-15m, as these need a clear line-of-sight to work. This includes no incursion into the Fresnel zone, which is a concentric ellipsoid of revolution which defines a volume in the radiation pattern of a circular aperture. See below for a summary of this strategy, and a description of line-of-sight, and Fresnel Zone. Fig 1. Wide Area GPRS/3G Remote area connection failover from 3G to GPRS 900 / 1800 / 2100 MHz 30m Buildings Non-LoS Military Grade Infrastructure Wireless Mbit long distance backhaul technology 10m-30m Buildings & Lamp Columns Multiple Connection Technologies (5000 & 7000 Series) Link technology to connect tall buildings and lamp columns 5 GHz 10m Lamp Columns Backhaul Connections CCTV and backhaul wireless 3m-4m Traffic Lights Real-time Military Grade Wireless Street-level wireless (traffic lights, VMS signs etc) 2.4 GHz Hotspots (802.11) Public hotspot access Ground Level Copper & Fibre Networks Wired connections offer backhaul for the mesh Cable Fig2. FRESNEL ZONE NON Lineof-Sight NEAR Lineof-Sight GOOD Lineof-Sight

4GHz Mesh4G radios, installed at 3m height for ease of installation, as the signal will be able to pass through any vehicles that could stop next to a radio.

5 Case Studies There are a number of councils around the UK who are implementing wireless networks for their on-street applications. Below are a few who have implemented a Mesh4G solution, along with the application they are using it for. Coventry City Council Traffic Lights, VMS Signs, CCTV, RTI Edinburgh City Council Traffic Lights, ANPR Cameras Fife City Council Traffic Lights, GreenWave Glasgow City Council Traffic Lights Hertfordshire City Council Information Points Kent County Council Traffic Lights and CCTV North Lincolnshire County Council Traffic Lights Suffolk County Council Traffic Lights and CCTV Hampshire Fire and Rescue Service On the ground communications We will focus on two cities that are currently using the Mesh4G solution Glasgow City Council Currently installed over 350 nodes Providing communications for traffic lights Network up and running for last 6 years Plans to extend network by installing a further 1000 nodes, and to add on ANPR cameras and car park controllers Glasgow Coverage

Coventry City Council Traffic Lights, VMS Signs, CCTV, RTI Edinburgh City Council Traffic Lights, ANPR Cameras Fife City Council Traffic Lights, GreenWave Glasgow City Council Traffic Lights

6 Coventry City Council Currently installed over 150 nodes Providing communications for traffic lights, VMS signs, bus stops and CCTV cameras Network up and running for last 3 years Plans to extend network by installing up to 200 nodes Coventry Coverage Conclusions To make the most of UTMC for the council area, there is a need to provide communications for the many different on-street applications. Ideally this will be a digital network; however it will be expensive to upgrade all fixed lines from analogue to digital. Wireless technology provides a communication path, whilst reducing on-going revenue costs to the council. For secure, robust, real-time communications you need to look at proprietary wireless solutions, i.e. Mesh4G

many different on-street applications. Ideally this will be a digital network; however it will be expensive to upgrade all fixed lines from analogue to digital.

communication over wireless link handling mobile user who changes point of attachment to network

communication over wireless link handling mobile user who changes point of attachment to network Wireless Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers! computer nets: laptops, palmtops, PDAs, Internet-enabled phone promise anytime untethered Internet