NewsNOW Metro Newsletter : January 2006 - Wireless Cities
Secure Wireless Traffic Lights save councils £100,000’s
Councils have always had to pay ongoing revenue costs of £100,000’s per year for leased line connections to their traffic lights, CCTV equipment, VMS signs and other council controlled applications. Now, with Mesh4G™ technology, councils can cut down on leased line connections by going wireless. Mesh4G™ incorporates a secure, military grade wireless meshing system, developed in the US with over $350 million of funding. This technology is starting to make its presence known across the UK.
Using Mesh4G™, councils are seeing the biggest savings in wireless traffic light systems. 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 can be completed within the hour.
No major engineering is required and the traffic light can now communicate with devices such as other traffic lights or central servers. This removes the requirement for a leased line connection, and ongoing revenue costs are dramatically reduced.
Starting with just a few nodes, the network is then completely scalable, able to handle 1,000’s of traffic lights, or any other device that needs to be wirelessly enabled. Each Mesh4G™ device has a range of around 500m, at least twice the normal distance of standard wireless devices. Mesh4G™ nodes can all act as repeaters that retransmit the signal from the access point that is connected to the backbone network. A single Mesh4G™ node can be five to ten hops away from the access point and each access point can host 100’s of Mesh4G™ nodes, this allows the range of the network to be greatly extended. 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 further wireless repeaters can be used.
Devices are then installed within range of any of these wireless points to provide services including access terminals for traffic lights, CCTV, variable message signs, bus stops, i-Kiosks™ to name a few.
Wireless CCTV can reduce cable connection costs by at least 50%
Mesh4G™ technology can be implemented in city centres for centrally managed criminal justice CCTV. Being able to centrally view images and control static cameras across a city has many advantages. Authorities are able to manage CCTV images in real time and deal with incidents as soon as they happen.
By using Mesh4G™ technology, existing fibre cables for all CCTV cameras that have line of sight (LoS) to other cameras can be replaced with a wireless connection therefore reducing cable connection costs by at least 50% for every two cameras wirelessly connected.
CCTV on Buses
NOW Wireless has tested a feature of Mesh4G™ that allows live CCTV to be transmitted from moving vehicles to bus depots, inspectors and council offices.
The technology allows a device to be installed on a bus which stores the video images from up to 8 cameras on a local hard drive whilst streaming the data to council offices or allowing an on-demand viewing of the cameras. With this technology drivers doing late night shifts can be monitored whenever an event occurs or when the driver is close to known trouble spots.
The cameras continuously store data on their local hard drive which is downloaded to a central server either on a continuous basis, overnight or on detection of an incident. In addition the data can be stored from cameras in real time at a lower data rate than the real time traffic. Communications can be either via a Mesh Network or via a 3G/GPRS network.
Other uses of a Mesh4G™ Network
As well as the council managed applications that Mesh4G™ has been implemented for, such as traffic lights, CCTV, RTI systems and hotspots, there are a number of other applications that make use of the unique features of Mesh4G™. The most common applications are for emergency response units, law enforcement units, telematics networks and sensor networks.
Whilst the emergency services are running on the Mesh4G™ network they are ensuring secure and reliable communication, such as the fastest route to an incident or details of an emergency, to emergency vehicles.
Also, each division is taking advantage of the different features that Mesh4G™ offers. For example, the Fire Service is using the location and tracking feature. An incident at a multi-story structure, or sprawling warehouse facility, can make reliable communications difficult. Mesh4G™ has developed a self-forming, self-healing technology that automatically creates a wireless broadband network at an incident. No existing network infrastructure is needed. This network also offers built-in position location capabilities that do not rely on GPS satellites. This means that personnel can be instantly located - even inside multi-story buildings. By simply providing each First Responder with a small, lightweight Mesh-Enabled device in their coat pocket and drawing a quick map of the site on a PC or tablet at the Incident Centre, the movement of these people can be graphically tracked in real time. Incapacitated personnel can be quickly identified, located, and rescued from dangerous situations. This implementation can ultimately save lives.
Police are taking advantage of Mesh4G™ devices in moving vehicles to transmit and receive CCTV images on the move. As Mesh4G™ works at up to speeds of up to 250 mph, officers get real-time access to databases, surveillance cameras and reporting tools that enable them to be more efficient whilst in the field. Broadband connectivity keeps them more informed of incident situations, increasing the safety of the officers and the public. It is an ideal replacement and upgrade for the CDPD network. Mesh4G™ offers between 10 and 50 times the bandwidth of this aging cellular data solution.
Mesh4G™ Technology
Mesh4G™ technology leverages patented and proven routing techniques originally developed for battlefield communications, and was developed with over $350 million of funding to become a secure enterprise wireless product. Mesh4G™ networking is typically implemented in two basic modes: infrastructure and/or client meshing. Infrastructure meshing creates wireless backhaul mesh among wired access points and wireless routers. Client meshing enables wireless peer-to-peer networks to form between and among client devices and does not require any network infrastructure to be present. In this case, clients can hop through each other to reach other clients in the network. This is achieved by using the Scalable Routing protocol, which enables dynamic, self-forming, self-healing, hopping routing between participating nodes in an ad-hoc (mesh) network. The situation-aware routing algorithms used in the Scalable Routing protocol greatly enhance the scalability of the network, whilst supporting high mobility in real world, wide area networks
Another proprietary protocol is Adaptive Transmission. The purpose of Adaptive Transmission 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.
Instead of broadcasting at one frequency, Mesh4G™ networks use a Quad Channel Military Radio (QCMR) Platform. QCMR radio technology uses Direct Sequence Spread Spectrum (DSSS) and operates in the ISM II 2.4 GHz bands. This radio is specifically designed and optimized for wide area, mobile mesh networking systems. It incorporates a multi-channel MAC that enables support for a higher density of meshed users than single channel MAC radios. Position/location technology is built-in to the QCMR radio and does not rely on GPS.
Finally, Mesh4G™ Positioning System technology offers 3-D position, location and tracking capabilities without the use of GPS satellites. Position location information, accurate to within +/- 10 meters, is generated in less than one second at mobility speeds of up to 250 mph.
The problems with 802.11b/g and the solution of Mesh QCMR
The 802.11 radio protocol was designed to provide a cost effective alternative to the piece of LAN cable between the wall and the user’s computer. When 802.11 was being designed, it was expected that the radio would be deployed indoors and the computer would remain relatively immobile. Subsequently, 802.11 was designed to provide very high data rates over short distances to stationary computers using a very low cost, low powered radio.
However, 802.11 has very little immunity from either self-induced or externally generated interference. These and other trade-offs were made to reduce the cost of 802.11. Unfortunately, it also worked to limit radio performance in such a way as to render 802.11 unusable in wide area mobile applications. Current 802.11 technology provides an excellent short range, fixed wireless solution as long as the required level of performance can be supported within the restrictions of these inherent limitations.
On the other hand, QCMR broadband radios are optimized specifically for wide area, mobile ad-hoc networking applications. With origins based on military specifications and requirements, it was designed to provide reliable communications under the most demanding battlefield conditions.
QCMR radios benefit from having a high performance RF (Radio Frequency) front end that includes capabilities such as multi-tap rake receivers (commonly found in cell phones) and real-time equalisation algorithms to compensate for the rapidly varying RF environments typically encountered in real-world mobile environments.
QCMR mobile broadband radios also incorporate increased error correction capability- again necessary for wide area and mobile communications. Rather than the typical maximum of 100m for line of sight (LoS) transmissions for 802.11, QCMR radios have a range of 500m LoS. Both of these ranges are typical when using omni-direction antennas.
Enhanced interference rejection and signal sensitivity allow QCMR-based networks to provide multi-megabit data rates at speeds up to 250 mph, whereas 802.11 drops the radio link at about 20 mph under real world Multipath conditions. Its multi-channel MAC and Phy are optimized to meet the scalability and reliability required in mission critical mesh networks. RF challenges encountered in wide area mobile networks such as Doppler shifting, rapid Raleigh fading and Multipath are handled efficiently by the QCMR radio..