awareness Contention between neighbors in carrier- sensing range - PowerPoint PPT Presentation

Motivation: Contention- awareness Contention between  neighbors in carrier- sensing range (c- B C A neighbors) Transmission at a node may  consume bandwidth at its c- neighbors A new flow may affects the  QoS of existing flows at its Carrier-sensing range c-neighbors Transmission range

Motivation: Contention- awareness  Local achievable bandwidth Achievable, but may  B C A degrade c- neighbors’ QoS  C-neighborhood available bandwidth Allowable bandwidth  Carrier-sensing range that does not affect c- Transmission range neighbors’ QoS

Motivation: Contention- awareness  Nodes have different views of the wireless channel B C A D A node only knows its  local bandwidth A node can not know  the available bandwidth at its c- Carrier-sensing range neighbors Transmission range C-neighborhood  signaling

Motivation: Contention- awareness E  Multiple nodes on a D A B C route contend at the F same location  Each node consumes bandwidth that equals the flow rate Carrier-sensing Range  Contention count (h) Transmission Range

Other Approaches Existing Approaches Limitations: Not   contention-aware SWAN  Local achievable Only local free or   bandwidth = idle achievable bandwidth channel bandwidth is considered Insignia  No consideration of  Achievable bandwidth  contention between = unreserved nodes on the same bandwidth route VMAC  No consideration of  Idle channel bandwidth  contention between = achievable bandwidth realtime traffic and best effort traffic

Contention-aware Admission Control Protocol (CACP)  Components  Route discovery  Admission control  Resource reservation  Mobility and QoS violation management

Route Discovery  Source Routing  Pin a flow to a route with enough resources  Supports traffic splitting & load balancing  Route request phase  Route request messages flood the network  Route reply phase  Route reply messages sent along the reversed route

Admission Control  Admission control combined with route discovery  Route request phase  Partial admission control on receiving a route request message  Route reply phase  Full admission control on receiving a route reply message

C-neighborhood Admission Control  Broadcast an admission E request message to c- D A B C neighbors F Multihop: CACP-Multihop  G Enhanced Power: CACP-  H Power  Admission rejection if not enough resources Carrier-sensing Range  Timeout if no admission Transmission Range rejection

Example: Route Request  Example of CACP Node A B C D B D C-neighbor set C A

Example: Route Request  Partial admission control Node A B C D B D C-neighbor A set Rt-Req C A

Example: Route Request  Partial admission control Node A B C D B D C-neighbor B A A Rt-Req set B C A

Example: Route Request  Partial admission control Node A B C D B D C-neighbor B A A B Rt-Req set C B C C A

Example: Route Reply  Full admission control  Local admission control Node A B C D B D C-neighbor B A A B Rt-Reply set C B C D C A

Example: Route Reply  Full admission control  Local admission control  C-neighborhood admission control (enhanced power) Node A B C D B D C-neighbor B A A B Ad-Req set C C B C Ad-Req D Ad-Req C A

Example: Route Reply  Full admission control  Local admission control Node A B C D B D C-neighbor B A A B set C C B C Rt-Reply D D C A

Example: Route Reply  Full admission control  Local admission control  C-neighborhood admission control (enhanced power) Node A B C D B D Ad-Req C-neighbor B A A B Ad-Req set Ad-Req C C B C D D C A

CACP Example: Route Reply  Full admission control  Local admission control Node A B C D B D C-neighbor B A A B Rt-Reply set C C B C D D C A

Example: Route Reply  Full admission control  Local admission control  C-neighborhood admission control (enhanced power) Node A B C D B D C-neighbor B A A B set Ad-Req C C B C D D Ad-Req C A

Example: Flow Starts  Periodically refresh resource reservation  Monitor link breaks Reroute   Monitor QoS violation events Reroute or decrease QoS requirement  Node A B C D B D C-neighbor B A A B Data Data set C C B C Data D D C A

Evaluation  Metrics  Bandwidth violation Throughput - packet generation rate at  source Throughput guarantees   Total network throughput Bandwidth utilization   Control message overhead  Packet delay

Evaluation: Simulation Setting  Compare CACP with DSR  SWAN  No c-neighborhood admission control  bandwidth consumption=flow rate  1000m  1000m Network Area # of nodes [20,180] Flow rate (pkts/s) [10,50] Packet size (Byte) [100,1000] Max speed (m/s) 5 Pause time (s) 10 # of flows 20

Evaluation: Throughput Guarantees QoS violation 0 Bandwidth violation rate (pkts/s) -10 -20 CACP-Multihop -30 CACP-Power -40 SWAN -50 DSR -60 -70 -80 -90 -100 20 40 60 80 100 120 140 160 180 Number of nodes  Bandwidth violation=Throughput- packet generation rate at the source

Evaluation: Network Utilization Total network throughput 140 CACP-Multihop 130 CACP-Power 120 SWAN Throughput (pkts/s) 110 DSR 100 90 80 70 60 50 40 20 40 60 80 100 120 140 160 180 Number of nodes