mesh4g Wireless








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 fifteen 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.



Mesh4G™ Scalable Routing

At the heart of Mesh4G™ ad-hoc networking technology is a highly efficient routing protocol designed specifically for use in Multi-Hopping™ wireless Mesh4G™ networks – the Mesh4G™ Scalable Routing protocol. This protocol is designed to work efficiently with or without centralized wireless infrastructure equipment.

Scalable Routing technology enables dynamic, self-forming, self-healing, Multi-Hopping™ routing between participating nodes in an Mesh4G network. This protocol is a hybrid routing approach that leverages proactive and reactive routing techniques via situation-aware networking. With this methodology , network topology dynamics, local RF conditions and degree of node mobility influence the routing metrics used on a moment by moment basis.

The Scalable Routing protocol is self-optimizing and delivers ultra-fast route convergence for mobile or RF hostile networks, while minimizing overhead on a per node and system wide basis. This unique technique reduces the flooding overhead and latency usually associated with the route discovery process of classical reactive protocols, as well as the high routing overhead usually associated with classical proactive protocols. The situation-aware routing algorithms used in this protocol greatly enhances the scalability of the network, while supporting high mobility in real world, wide area networks. In addition, the algorithms used have been demonstrated to be free of routing loops in all topology and network conditions.

Scalable Routing technology leverages a real-time assessment of connectivity and other environmental factors to determine routes between nodes as well as end-to-end paths through the network. It learns of these conditions via a set of metrics supplied by Adaptive Transmission protocol services (see below). This continuous assessment of network and RF conditions also helps it accomplish “make before break” routing, resulting in smooth handoffs, seamless connectivity, and reliable communications for high speed mobile networks. Strong interaction with Adaptive Transmission protocol services also enables the Scalable Routing protocol to characterise the “bi-directionality” of a link. That is, the extent to which a wireless link can support symmetric data rates to and from a pair of nodes. The ability to characterise and assess asymmetric links is critical for real world wireless routing.

Adaptive Transmission Protocol Service

Many possible environmental conditions can interfere with data transmitted wirelessly, particularly broadband data in high speed mobility situations. Multipath, shadowing, fast fading, and interference (both intentional and unintentional) can all cause excessive packet loss at the receiver.

To deal with these conditions, the transmitter will be instructed to back down its data rate for a period of time. However, these RF conditions can appear on a highly dynamic basis. If the data rate is decreased for longer than the condition exists, link reliability may be satisfactory, but throughput is not maximized. If the data rate is raised too quickly while the condition continues, the resulting packet loss can also lead to poor data throughput. The purpose of Adaptive Transmission protocol services is to enable the Scalable Routing protocol to balance the requirements of a reliable transmission whilst assuring the highest data throughput rate possible on a packet by packet basis.

In addition to providing link quality metrics, these services inform the Scalable Routing protocol of the impact that transmit power level has on network capacity for a given link. For example, the high transmit power required by a particular link may create interference and uses channel resources (i.e. spectrum) unnecessarily. Adaptive Transmission protocol services provide multiple physical layer statistics to the Scalable Routing protocol, which then becomes power-aware. At the same time, these services actively determine the fastest data rate that can be achieved on a packet by packet basis for each link.