Wireless Mesh Networks Technologies

wireless mesh networking technology for commercial and industrial customers and how to design wireless mesh network
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ImogenCameron,France,Teacher
Published Date:14-07-2017
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Wireless Mesh Networks Technologies: Architectures, Protocols, Resource Management and Applications Eugen Borcoci University POLITEHNICA Bucharest Electronics, Telecommunication and Information Technology Faculty Eugen.Borcocielcom.pub.ro th INFOWARE Conference , August 22- 29 , Cannes, France1. WMN Introduction  WMN general characteristics  WMNs – can be seen as an extension of multi-hop Ad-Hoc networks; each node can communicate directly or inf=directly with one or more peer nodes  WMN relationship with other multihop wireless network  Source: Ed.Yan Zhang , Jijun Luo, Honglin Hu, WIRELESS MESH NETWORKING, Auerbach Publications, 2007 Scope of this presentation INFOWARE Conference, August 22- 29th, Cannes, France Slide 61. WMN Introduction  WMN general characteristics  WMN do not require centralized access points to mediate the wireless connection  WMN Multi-hop feature – increases the coverage area and link robustness of existing Wi-Fi’s; ( if the correspondent nodes are not in the wireless transmission range of each other)  Hope to complement and improve the performance/costs for WPANs, MANETs, WLANs, WMANs  WMNs are in significant progress; numerous deployments already exist, to deliver wireless services for a large variety of applications in personal, local, campus, and metropolitan areas  WMNs wireless nodes: mobile or fixed  Basic types of nodes: mesh routers (MR) and mesh clients (MC), where MR – establishes an infrastructure backbone for clients  Actually one have: Wireless Mesh routers, Gateways, Printers, Servers, Mobile or Stationary clients (terminals) INFOWARE Conference, August 22- 29th, Cannes, France Slide 71. WMN Introduction  The WMN may be connected to:  the Internet through gateway/routers  Other networks through Gateways/Bridges  End hosts and routing nodes might be distinct  Routers are usually stationary (except hybrid WMNs where they can be also mobile)  Mesh clients  can be either stationary or mobile  can form a client mesh network among themselves and/or together with MRs  Traffic: user-to-gateway or, user-to-user  WMNs : dynamically self-organized and self-configured systems (one node can automatically establish and maintain the mesh connectivity) INFOWARE Conference, August 22- 29th, Cannes, France Slide 81. WMN Introduction  Wireless Mesh Networks Technolgies  WMNs technologies:  Initially: extension of IEEE 802.11 WLANs  today hybrid technologies can cooperate in mesh topology  the APs are considered as the nodes of mesh; (they may be heterogeneous and inter- connected in a hierarchical fashion)  The integration and interconnection of different technologies in/with WMNs (Internet, cellular, IEEE 802.11, IEEE 802.15, IEEE 802.16, sensor networks, etc.), can be achieved through the gateway and bridging functions in the MRs  WMN: many open issues and research challenges related to (non-orthogonal list of issues):  Architectures and Protocol layers  PHY and MAC specific issues  Scheduling, Multi-channel, multi-radio  Cognitive radio  MIMO, Directional and smart antennas systems  Capacity and coverage  Scalability (major point)  Routing  Resource management and QoS capabilities  Cross-layer optimization  Security, etc. INFOWARE Conference, August 22- 29th, Cannes, France Slide 91. WMN Introduction  WMN usage scenarios  WMN economical advantage: low cost technology  WMNs – Broadband Networking services  Metropolitan Area  Home  Community and Neighborhood  Enterprise  Campus  High level services scenarios  Security and Surveillance Systems  Building Automation  Health and Medical Systems  Transportation Systems  Community networks  City networks  ….. INFOWARE Conference, August 22- 29th, Cannes, France Slide 102. Basic architectures and challenges  WMN taxonomy  Major architectural choices  Topology based  Flat  Hierarchical (clusters)  Technology based  Homogeneous (e.g. IEEE 802.11 only)  Heterogeneous (e.g IEEE 802.11, 16, 15)  Node based  Infrastructure/Backbone WMNs(fixed/nomadic infrastructure)  Client WMNs (host based)  Hybrid WMNs INFOWARE Conference, August 22- 29th, Cannes, France Slide 122. Basic architectures and challenges  Infrastructure/Backbone WMNs  Mesh Routers (MR) : compose together a mesh infrastructure/ bacbone for clients (connected to them ) using different RT ( mainly 802.11)  Actually one has a wireless distribution system replacing the wired one in 802.11  MRs form a mesh of self-configuring with self-healing links  MR/GW: additional gateway/bridge functionality, for connection to the Internet  Clients with Ethernet I/F can be connected to MRs via Ethernet links  Clients with the same radio technologies as MRs - can directly communicate with MRs  If different RT are used, clients must communicate with the base stations that may have Ethernet connections to mesh routers. INFOWARE Conference, August 22- 29th, Cannes, France Slide 132. Basic architectures and challenges  Infrastructure/Backbone WMNs (cont’d)  Mesh Infrastructure/Backbone WMNs : currently the most used type.  Example:  community and neighborhood networks  The MRs can be placed on the roof of houses in a neighborhood, which serve as access points (APs) for users inside the homes and along the roads.  Typically, two radios are used in the routers,  for backbone communication  for user communication  The mesh backbone communication can be established using extended-range communication techniques including directional antennas. INFOWARE Conference, August 22- 29th, Cannes, France Slide 142. Basic architectures and challenges  Client WMNs  Similar to Ad hoc networks  P2P-style mesh networks among client devices  Client nodes should:  perform routing and configuration functionalities  provide end user applications to customers  A packet destined to a node in the network , hops through multiple nodes to reach the destination  Usually have a single type of radio on devices  The requirements on end-user devices  Higher when compared to infrastructure meshing since, the end-users must perform additional functions (e.g. routing and self-configuration) INFOWARE Conference, August 22- 29th, Cannes, France Slide 152. Basic architectures and challenges  Hybrid WMN  It is a combination of infrastructure and client meshing.  Mesh clients can access the network through MR as well as directly meshing with other mesh clients   The infrastructure may provides connectivity to other networks  Internet, Wi-Fi, WiMAX,cellular, and sensor networks  The routing capabilities of clients provide improved connectivity and coverage inside the WMN  The hybrid architectures will be probably, the most applicable case in the future INFOWARE Conference, August 22- 29th, Cannes, France Slide 161. 2. Basic architectures and challenges  Hybrid WMN- example INFOWARE Conference, August 22- 29th, Cannes, France Slide 172. Basic architectures and challenges  Hybrid WMN - real life example  Source: Akyildiz, I.F., Wang, X. and Wang, W., Wireless Mesh Networks: A Survey, Computer Networks Journal (Elsevier), March 2005 INFOWARE Conference, August 22- 29th, Cannes, France Slide 182. Basic architectures and challenges  WMN elements: links  Link functions: intra-mesh, access (to/from stationary or mobile client stations), internet  Client-to MR links  Link types  Wired: Bus (PCI, PCMCIA, USB), Ethernet, Firewire, etc.  Wireless: 802.11x, 802.16x, 802.15, proprietary  Link mode: Point-to-Point (PP) or Point-to-Multipoint (PMP)  Links should have enough capacity to avoid traffic saturation  In general- access links: connect entities different from MR-MR  MR to MR (backbone) links  Link types  Wireless: 802.11x, 802.16, 802.15, Proprietary  Link mode: Usually multipoint to multipoint; set of point to point  Could be traffic saturated  WMN Gateway to Internet links (backhaul)  Link types  Wired: Ethernet, TV Cable, Power Lines  Wireless: 802.16, Proprietary  Link mode: Point to Point or Point-to-Multipoint  Must be designed with enough capacity to avoid bottlenecks INFOWARE Conference, August 22- 29th, Cannes, France Slide 192. Basic architectures and challenges  WMN elements (cont’d)  Mesh Routers (MR)  They contain additional routing functions to support mesh networking  They usually have multiple wireless interfaces built on the same or different RAT  Mobility: Stationary (e.g. rooftop) ; Mobile (e.g., airplane, busses/subway)  MRs can achieve the same coverage as a conventional router • with lower transmission power due to multi-hop feature  Do not originate/terminate data flows  For large WMNs, many MRs are needed, hence, cost can be an issue  Implementation: MRs may be based on different embedded systems, e.g.: PowerPC or Advanced Risc Machines (ARM) INFOWARE Conference, August 22- 29th, Cannes, France Slide 202. Basic architectures and challenges  WMN elements (cont’d) Gateways (GW)  The gateway/bridge (GW-B) functionalities enable the integration of WMNs with other wireline or wireless networks such as: Internet, cellular, wireless sensor, Wi-Fi, WiMAX  Multiple interfaces (wired & wireless)  Mobility: Stationary (e.g. rooftop) – most frequent; Mobile (e.g., airplane, busses/subway)  Serve as (multi-hop) “access points” to user nodes  Few GWs are needed, (they are more expensive) INFOWARE Conference, August 22- 29th, Cannes, France Slide 212. Basic architectures and challenges  WMN elements (cont’d) Clients/users  The sources/destinations for data traffic flows in the network  Typically have one interface  Mobility: Stationary or Mobile  Connected to the WMN through MRs (or directly to GWs)  Examples of mesh clients: Laptop, PDA, Wi-Fi IP Phone and Wi- Fi RFID Reader  Nodes (e.g., desktops, laptops, PDAs, PocketPCs, phones, etc.) having wireless NICs can connect directly to MRs  Clients with wireline NICs can access MRs by connecting through, e.g., Ethernet  WMNs enable users be always-on-line anywhere, anytime INFOWARE Conference, August 22- 29th, Cannes, France Slide 222. Basic architectures and challenges  WMN versus Ad-hoc Networks (MANET)  Routing and network configuration  MANET: end-user devices additionally perform routing and configuration functionalities for all other nodes  WMN: Mesh routers perform routing and configuration  Consequence for WMNs • load on end-user devices is significantly decreased • lower energy consumption hence additional capabilities to mobile and energy constrained end-users. • limited end-user requirements (decreasing the cost of devices that can be used in WMNs).  Mobility capabilities  MANET: topology is frequently changing, depending on the users’ movement - additional tasks for routing protocols and network configuration  WMNs- MRs infrastructure : WMN can be easier managed and configured ( MRs are usually fixed or nomadic)  Still the mobility of end-users is supported INFOWARE Conference, August 22- 29th, Cannes, France Slide 232. Basic architectures and challenges  WMN versus Ad-hoc Networks (MANET) (cont’d)  Usage of Multiple Radios (MRd)  MRs can be equipped with multiple radios to perform routing and access functionalities.  Consequence: possibility to distinguish between two main types of traffic • routing and configuration traffic is performed between MRs • access traffic to the network from clients (can be carried in a different radio) • MRd can improve the WMN capacity versus MANET  Relationship 802.11-MANET and WMN  MANETs can be considered as a subset of WMNs.  IEEE 802.11 existing techniques developed for MANET are applicable to WMNs ( with some modifications for better performance). INFOWARE Conference, August 22- 29th, Cannes, France Slide 242. Basic architectures and challenges  Significant WMN design factors with impact on performance/cost  PHY - Radio techniques and MAC  Approaches have been proposed to increase capacity and flexibility of wireless systems  Directional and smart antennas, MIMO and multi-radio/multi- channel systems  MIMO : key technologies for IEEE 802.11n - high speed extension of Wi-Fi  Multi-radio chipsets and their development platforms are available on the market  Advanced RT such as reconfigurable radios, frequency agile/cognitive radios, software radios are in development – allowing dynamic control of PHY layer INFOWARE Conference, August 22- 29th, Cannes, France Slide 25