1. Anumol.K.J Roll No:30

2.  Mesh radio is an innovative approach to delivering broadband access to residential and small business customers.  It makes every customer’s equipment capable of providing service to its neighbours. provider.  It is independent of any existing service provider. Contd….

3.  It will let them watch movies on demand,broadcast quality videos and download from internet at a blistering speed [4-25Mbits/sec].  Each Subscriber linked to several other subscribers nearby by low-power radio transmitters;these in turn connected to others,forming a network or mesh.  It is used to increase the reach of cable networks without incurring the expense of digging up streets. Contd….

5.  Originally developed for military applications.  It is a communication network made up of radio nodes organized in a mesh topology.  The coverage area of radio nodes working as a single network is called mesh cloud. Contd….

6.  Wireless mesh networks can be implemented with various wireless technology including 802.11, 802.16, cellular technologies or combinations of more than one type.  Each wireless device is capable of acting as a router as well as an end station.  Packet routing is similar to the way packets go around the Internet. Contd…

7.  The number of links between any two nodes are potentially much greater than in a wired network, since the actual configuration of a particular wireless mesh need not be determined until it is actually moving data.  Paths through the network can change from moment to moment in response to varying traffic loads, radio conditions e.t.c.

9.  1-Radio Mesh  Dual-Radio with 1-Radio Backhaul Mesh  3 Radio with 2 Radio Backhauls Mesh

10.  This configuration uses one radio channel both to service clients and to provide the mesh backhaul.  This provides worst service of all options,since both backhaul and service compete for bandwidth.  This architecture suffer from the send-receive-wait cycle. Contd…

12.  It is referred to as a "1+1" network, since each node contains two radios, one to provide service to the clients, and one to create the mesh network for backhaul.  The "1+1" name indicates that these radios are separate from each other.  These two radios can operate indifferent bands. Contd…

14.  This architecture provides separate backhaul and service functionality and dynamically manages channels of all of the radios so that all radios are on non-interfering channels.  It provides better performance of any options. Contd…

17.  There are three different topologies.  Point-to-Point Topology.  Point-to-Multipoint Topology.  Mesh Topology (multipoint-to- multipoint).

18.  two buildings connected directly to one another through a point-to-point (PtP) communications link.  For situations where long-distance links are required, a PtP architecture may be the best solution.  It provides the highest data rates. Contd…

19.  Each communication link consist of an individual pair of broadband wireless routers, and requires the dedicated use of an RF channel. Fig. Point-to-Point link

21.  It allows multiple remote buildings to share a connection back to a single, central base station.  Easily scale up the network.  It causes "hidden transmitter interference".  To address this problem, some base station products can operate in a polling mode.

23.  It is referred to as peer-to-peer or multipoint-to- multipoint topologies.  Enables network expansion.  Provides a self-healing architecture.  Reduces implementation and operating costs.

24. Suitability in Industrial Applications Topology Reliability AdaptabilityScalability Point-to-PointHighLowNone (two end points) Point-to-MultipointLow Moderate (7-30 end points) Mesh NetworksHigh Yes (thousands of end points)

25.  It has flexible architecture.  It is based on Mesh networking or multi-hop networking for moving data efficiently between devices.  In a multi-hop network, any device with a radio link can serve as a router or AP. Contd…

26. Fig. Architecture proposed by Radiant Networks in California Contd..

27.  Trunk Network Connection Points (TNCPs) link the radio access Mesh to the trun communications network.  Each of the TNCPs will serve a number of Mesh Insertion Points(MIP).  These consist of a standard Customer Node (CN),which can set up connections to other customers, and equipment for multiplexing the signals to and from that customer node onto a link to the TNCP. Contd…

28.  Customer Node(CN) not only provides service for that customer but also handles transit traffic from other customers.  It consists of an outdoor radio unit and an indoor service presentation unit.  The Mesh will also include a number of Seed Nodes (SNs).  These are the same as the customer Nodes except that there are no customers connected to them. Cond…

29.  The operator installs them at strategic locations to extend coverage to a large number of potential customers.  The role of a seed node is to establish a path back to an MIP (perhaps via other SNs).  It therefore must have atleast one line of sight to an MIP or another seed.

30.  Fewer central stations, Non-line-of-sight With Mesh Radio each new customer only needs to be within sight of at least one other customer, not within line of sight of the base station as with other technologies.  No need for high Sites It is no longer necessary to deploy network connection points on the highest buildings or hilltops. Contd…

31. 3)Robustness  In a single-hop network, if the sole access point goes down, so does the network.  In mesh network architecture, if the nearest AP is down or there is localized interference, the network will continue to operate; data will simply be routed along an alternate path. Contd…

32. 4) Minimum upfront network investment for deployment  With traditional fixed wireless systems, coverage, even to a few subscribers, depends on installing a significant number of base stations, so that an operator is faced with high initial costs.  With Mesh Radio new customers can be connected with a very low density of deployed 'seed' nodes, which provide initial coverage. Contd..

33. 5) Fault-tolerance, Self-healing architecture  Meshes are very adaptable to failures in nodes or dropouts in radio coverage - traffic is simply re- routed dynamically.  Each mesh node is aware of the primary optimal path, the secondary path, and every tertiary path a packet may follow to reach its intended destination.  If a building node is removed from the network, each node rapidly learns of the change and defines a new optimal path for its traffic. Contd..

35. 6) Higher bandwidth  In wireless communication bandwidth is higher at shorter range, because of interference and other factors that contribute to loss of data as distance increases.  One way to get more bandwidth out of the network, is to transmit data across multiple short hops. Contd..

36. 7) Spatial reuse  In a single-hop network, devices must share an AP.  If several devices attempt to access the network at once, a virtual traffic jam occurs and the system slows.  In a multi-hop network, many devices can connect to the network at the same time, through different nodes, without necessarily degrading system performance. Cond….

37. 8) Spectrally efficient  By using Mesh Radio, radio spectrum is used up to 50 times more efficiently, because the 'narrow' beams are much less likely to interfere with each other.  This enabling massive increases in data capacity for end users at high customer densities Cond..

38. 9) Power  The substrate nodes of a mesh network can be built with extremely low power requirements, meaning that they can be deployed as completely autonomous units with solar, wind, or hydro power. 10) Integration  Mesh hardware is typically small, noiseless, and easily encapsulated in weatherproof boxes. Contd…

40. 11) Network Expansion  With mesh, each network node also acts as a repeater, or forwarding agent, for every other network node whose wireless signal it can hear.  Because each mesh node plays a dual role, adding additional nodes to the network is very simple.

41.  Time Bounded Behavior  If we're relaying traffic between a large number of nodes, the latency involved in this relaying can affect time-bounded traffic, like voice or video.  This problem is usually addressed via the routing protocols used to implement the mesh, but it is potentially a serious concern regardless. Contd..

42.  Security  If user traffic is traveling through intermediate nodes in a mesh, security is an issue.  Intermediate nodes might be able to eavesdrop on data not intended for them.

43.  A significant application for wireless mesh networks is VoIP.  By this, the wireless mesh may support local telephone calls to be routed through the mesh.  VoIP system uses session control protocol like SIP to set up and tear down of calls as well as audio codecs which encode speech allowing transmission over a mesh network as digital audio via an audio stream. Contd..

44.  Some current applications :  U.S. military forces are now using wireless mesh networking to connect their computers, mainly ruggedized laptops, in field operations. It enables troops to know the locations and status of every soldier or marine, and to coordinate their activities without much direction from central command. Contd…

45.  Electric meters now being deployed on residences transfer their readings from one to another and eventually to the central office for billing without the need for human meter readers or the need to connect the meters with cables.  The 66-satellite Iridium constellation operates as a mesh network, with wireless links between adjacent satellites. Calls between two satellite phones are routed through the mesh, from one satellite to another across the constellation, without having to go through an earth station. This makes for a smaller travel distance.

47.  Products based on point-to-point and point-to- multipoint topologies may not be well suited for industrial communications.  Mesh technology is reliable and redundant, and it can be extended to include thousands of devices.  In addition, these networks can be installed in hours instead of days or weeks.

48.  The self-configuring, self-healing networks are inherently less expensive to install and maintain.  P3M technology enables,a set of of mesh nodes to function without the presence of a root node.  Clients within the P3M mesh will be able to communicate with other through the MD4000 mesh nodes.