Multi-hop Wireless Network and Its Applications Junhee Lee Network Systems Lab. EECS, KAIST junhee@netsys.kaist.ac.kr Korea Advanced Institute of Science and Technology, Network Systems Lab. -1-
Wireless Networking Wireless Networking Single Hop Multi-hop Infrastructure-based Infrastructure-based Infrastructure-less 802.11 802.16 Multi-hop Cellular Networks Cellular Networks Wireless Sensor Networks Wireless Mesh Networks Mobile Ad Hoc Networks (MANET) Korea Advanced Institute of Science and Technology, Network Systems Lab. -2-
Mesh vs. Ad-Hoc Networks Ad-Hoc Networks Multihop Nodes are wireless, possibly mobile It may rely on infrastructure Most traffic is user-touser Wireless Mesh Networks Multihop Nodes are wireless, some mobile, some fixed It relies on infrastructure Most traffic is user-togateway Korea Advanced Institute of Science and Technology, Network Systems Lab. -3-
Mesh vs. Sensor Networks Wireless Sensor Networks Bandwidth is limited (tens of kbps) In most applications, fixed nodes Energy efficiency is an issue Wireless Mesh Networks Bandwidth is generous (>1Mbps) Some mobile, some fixed Normally not energy limited Resource constrained Resources are not an issue Most traffic is user-togateway Most traffic is user-togateway Korea Advanced Institute of Science and Technology, Network Systems Lab. -4-
WMN Architecture WMNs (Wireless Mesh Networks) consist of: mesh routers and mesh clients Mesh routers Conventional wireless AP (Access Point) functions Additional mesh routing functions to support multi-hop communications Usually multiple wireless interfaces built on either the same or different radio technologies Mesh clients Can also work as a router for client WMN Usually one wireless interface Classification of WMN architecture Infrastructure/Backbone WMNs Client WMNs Hybrid WMNs Korea Advanced Institute of Science and Technology, Network Systems Lab. -5-
Infrastructure/Backbone WMNs Infrastructure/Backbone WMNs Korea Advanced Institute of Science and Technology, Network Systems Lab. -6-
Hybrid WMNs Hybrid WMNs Korea Advanced Institute of Science and Technology, Network Systems Lab. -7-
WMN Characteristics Multi-hop wireless network Extend coverage with lower transmission power Provide non-line-of-sight (NLOS) connectivity Ad hoc network with self-forming, selfhealing, and self-organization capability Low upfront investment Easy deployment Fault tolerance Minimal mobility Mesh routers have minimal mobility Mesh clients can be stationary or mobile Korea Advanced Institute of Science and Technology, Network Systems Lab. -8-
WMN Characteristics Wireless internetwork Internetwork of heterogeneous wireless networks (e.g., Wi-Fi networks, WiMax networks, cellular networks, Zig-Bee networks etc.) Traffic pattern Most traffic is user-to-gateway or gateway-touser In ad hoc networks, most traffic is user-to-user Not an energy-limited network Mesh routers are usually AC-powered Energy efficiency is not an issue in protocol design Korea Advanced Institute of Science and Technology, Network Systems Lab. -9-
WMN Advantage Very low installation and maintenance cost. No wiring! Wiring is always expensive/labor intensive, time consuming, inflexible. Easy to provide coverage in outdoors and hard-to-wire areas. Ubiquitous access. Rapid deployment. Self-healing, resilient, extensible. Korea Advanced Institute of Science and Technology, Network Systems Lab. -10-
Application Scenarios Broadband home networking Korea Advanced Institute of Science and Technology, Network Systems Lab. -11-
Application Scenarios Community and neighborhood networking Korea Advanced Institute of Science and Technology, Network Systems Lab. -12-
Application Scenarios Enterprise networking Korea Advanced Institute of Science and Technology, Network Systems Lab. -13-
Application Scenarios Metropolitan area networking Korea Advanced Institute of Science and Technology, Network Systems Lab. -14-
Application Scenarios Public safety Korea Advanced Institute of Science and Technology, Network Systems Lab. -15-
Application Scenarios Sensor networking for environment monitoring (e.g., meteorological observatory network) Inchon MO Youngjong-Do Muei-Do Beacon (Seosoo-Do) Palmi-Do Sunmi-Do Jaweol-Do Deujeuk Buoy Deukjeuk-Do Do Bu-Do YoungHung-Do Daebu-Do Do Korea Advanced Institute of Science and Technology, Network Systems Lab. -16-
Application Scenarios Transportation systems Building automations Health and medical systems Security surveillance systems Spontaneous networking Korea Advanced Institute of Science and Technology, Network Systems Lab. -17-
Service Models Private ISP (paid service) City/county/municipality efforts Grassroots community efforts May be shared infrastructure for multiple uses Internet access Government, public safety, law enforcement Education, community peer-to-peer Korea Advanced Institute of Science and Technology, Network Systems Lab. -18-