Mesh4G™ OverviewTraffic Light Systems 
UK Councils have the unique opportunity to create wireless communication systems that cover whole cities.
Fixed line costs can be reduced significantly by utilising the existing infrastructure.
Enhanced service levels are provided to both the general public and council employees.
Capital costs are lower than those for civil engineering work of typical UTMC systems, and with no revenue costs.
RTI can be done with Mesh4G™ as it operates on moving vehicles. Bus Priority and Clear-Down issues are solved.
Scope of the Mesh4G™ Network can encompass RTI, Car Park Counters, Variable Message Signs, Information Kiosks, Bus Stops, Ticket Machines, Council Workers, Buses and CCTV.
Wireless For Councils
In the present wireless digital world, it is now possible to provide integrated communications for councils with no revenue component. With their physical infrastructure, Councils are in a very commanding position to install digital systems with a wireless infrastructure.
Traffic lights are not the only application to benefit from wireless; other areas are real-time passenger information, CCTV, parking ticket machines, variable traffic signs, Council workers, emergency services and schools.
With the advent of Urban Traffic Management and Control systems (UTMC), there is a need to provide information from the traffic light controller back to the Central Server. Either this is an existing system, based on serial communications which requires replacement, or a new communications connection. In most cases the use of a wireless system has an equal or lower capital cost than an equivalent cabled solution (taking into account the required civil engineering). In addition, the wireless solution does not incur a revenue cost.
For UTMC-connected traffic lights, a communications path must exist back to the control centre. This can be accomplished by the use of Mesh4G™ Network clusters. Traffic lights are connected via Mesh Nodes to each other, and then via an Access Point back to the Network Control Centre.
Each Mesh Node provides an opportunity for other devices to route through it, either by direct connection or by a wireless connection from a nearby node. CCTV cameras for traffic monitoring can be easily and cheaply connected this way. In fact, connections for multiple cameras can be put in place at one junction.
The Technology
Mesh4G™, a street-level wireless Mesh Network, provides a low cost connection between traffic lights, buses, Council employees, bus stops, CCTV, ticket machines, variable message signs and the Council offices. Traffic lights are converted from standalone operation by the installation of a wireless point in the control cabinet with a cable running to the nearest traffic pole. Just a small box with an aerial is installed, connecting to existing mountings on the pole, and installation is complete.
No major engineering is required and the traffic light can now communicate with devices such as other traffic lights or central servers.
The wireless device can communicate through up to five or more devices before reaching an Access Point, which then connects via a higher-level network to the Control Centre. The higher-level network can consist of ADSL, EPS9 circuits, 5GHz wireless or any other existing communications medium.
If a gap in reception is found then a Mesh Repeater can be used. Devices are then installed within range of any of these wireless points to provide services including access terminals for variable message signs, bus stops, etc.
Buses with a Mesh4G™ device installed can communicate with the city network, providing location information to a central server or communicating directly to bus stops and traffic lights. They in turn act as extra dynamic repeaters in the network, providing additional resilience. The more nodes that are deployed, the more traffic and resilience the system can deliver. Traffic does not all need to go to the centre; it may go from point to point as needed.
In out-of-town locations where a street-level Mesh Network is not required, connections using 5GHz can be made at a cost similar to or lower than the Mesh Nodes. If more equipment is needed at a later time then a Mesh4G™ Access Point can be installed and a local cluster of devices managed.
Wireless Traffic Lights
The disruption and cost of civil engineering work, together with the delays involved waiting for communications cable installation, have resulted in headaches for traffic managers. Great hopes were generated by the introduction of wireless technology; however, to date it has not resulted in effective systems. In short, the wireless technologies were not sophisticated enough to provide the resilience needed.
In the wireless world there are two levels of sophistication: on the one hand, the world of GSM and 3G, which have billions invested in their respective technologies. On the other, the 802.11 world uses $15 components and does not have the resilience needed for street-level deployments.
Five years ago, NOW Wireless reviewed the available technology to find a solution for street-level wireless. As the 2.4GHz band was licence free and capable of penetrating buildings, it provided the best solution. However, EC regulations limit the power of these networks to 100mW, whereas in the US and Far East power levels of 1 or 2W are commonplace. GSM handsets use 500mW–1W. Wi-Fi (802.11b/g) was investigated but it was found that, with only three non-overlapping channels and a very primitive radio, it was very easy to block. A person with a notebook computer could easily stop a Wi-Fi transmission. This solution ignored the security issues of Wi-Fi, which can be solved, but no solution was found for the blocking.
In our review, we found a military system which had had over $350 million invested in it. This technology was a Mesh4G™ Network which employed military-grade encryption and was designed to be resistant to all attempts to block it. This was one of the most complex wireless technologies we had seen, with four individual radios with multi-tapped receivers for dealing with reflections, as well as full Doppler correction to allow operation aboard moving vehicles (tested to 250mph). Each radio acted within the network to provide transmission of a signal from one point to another, selecting frequency and route according to available resources. Currently used by the US Military, a commercial lower cost version with a PCMCIA card in the sub-£500 category made this an obvious option.