Post on 15-Jan-2016
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 1
UC Berkeley WOW
Wireless Token Ring Protocol (WTRP)A Medium Access Control Protocol for
QoS Aware Wireless Networks
Mustafa Ergen, Duke Lee, Ruchira Datta, Jeff Ko, Roberto Attias, Anuj Puri, Raja Sengupta, Starvros Tripakis, and Pravin Variaya
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 2
UC Berkeley WOW
Automated Vehicle Platoon
Real-time safety critical control over ad-hoc network
Vehicles transmit control data in round robin every 20 ms
Wireless Quality of Service
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 3
UC Berkeley WOW
Merge Lane
Distributed solutionNeed wireless QOSAdmission control
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 4
UC Berkeley WOW
Motivations for WTRP
Quality of service (real time applications)
Distributed solution (robust against a single node failure)
Flexible topology (token ring can be created with Pico cells)
Safety critical applications (need fast recovery from failure)
No need for clock synchronization (compared to TDMA)
Partial connectivity (hidden terminal problem)
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 5
UC Berkeley WOW
Motivations for WTRP
Quality of service (real time applications)
Distributed solution (robust against a single node failure)
Flexible topology (token ring can be created with Pico cells)
Safety critical applications (need fast recovery from failure)
No need for clock synchronization (compared to TDMA)
Works on partial connectivity (no hidden terminal problem)
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 6
UC Berkeley WOW
Motivations for WTRP
Quality of service (real time applications)
Distributed solution (robust against a single node failure)
Flexible topology (token ring can be created with Pico cells)
Safety critical applications (need fast recovery from failure)
No need for clock synchronization (compared to TDMA)
Works on partial connectivity (no hidden terminal problem)
centralized (802.11 PCF, Bluetooth) distributed (token ring)
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 7
UC Berkeley WOW
Motivations for WTRP
Quality of service (real time applications)
Distributed solution (robust against a single node failure)
Flexible topology (token ring can be created with Pico cells)
Safety critical applications (need fast recovery from failure)
No need for clock synchronization (compared to TDMA)
Works on partial connectivity (no hidden terminal problem)
1 43 12
TDMA
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 8
UC Berkeley WOW
Motivations for WTRP
Quality of service (real time applications)
Distributed solution (robust against a single node failure)
Flexible topology (token ring can be created with Pico cells)
Safety critical applications (need fast recovery from failure)
No need for clock synchronization (compared to TDMA)
Works on partial connectivity (no hidden terminal problem)
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 9
UC Berkeley WOW
Additional Challenges From Wireless Medium
Partial connectivity (unable to hear all nodes in a ring)
Support for multiple rings
Self-managed admission control
Frequent packet loss, corruption
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 10
UC Berkeley WOW
Solutions: Connectivity TableEach node builds and updates connectivity table that contains information of all stations in its reception range, and transmission order of the nodes in its ring
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 11
UC Berkeley WOW
Solutions: Connectivity TableEach node builds and updates connectivity table that contains information of all stations in its reception range, and transmission order of the nodes in its ring
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 12
UC Berkeley WOW
Ring RecoveryB fails or moves out of range.
A tries to transmit to its successor (B) a specified number of tries and determine that communication link to B is bad.
A B C
DE
F
2. SET_PRED A
1. Retransmit TOKEN0. Transmit TOKEN
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 13
UC Berkeley WOW
Solutions: Unique Ring Address
Each ring has unique ring id based on unique MAC address of one of the stations of the ring.
1
1
7
7
5
5
44
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 14
UC Berkeley WOW
Solutions: Unique Priority of TokenBased on ring address and generation sequence number pair.
Station only accept token that has higher priority than the last token that the station has accepted.
ring address generation sequence …
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 15
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
11
1
61
2
2
6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 16
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
21
1
66
2
2
6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 17
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
22
1
66
6
2
6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 18
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
62
2
66
6
2
6
At next stepDelete token with generation sequence number 2 since the next node has seen token with generation sequence number 6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 19
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
66
2
66
6
6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 20
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
66
6
66
6
6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 21
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
66
6
76
6
7Token refreshed by owner
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 22
UC Berkeley WOW
Token Recovery (Multiple Tokens Resolution)
66
6
77
6
7
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 23
UC Berkeley WOW
Token Recovery (Ring Address Resolution)
66
6
76
6
6
Suppose that the owner of the token has failed
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 24
UC Berkeley WOW
Token Recovery (Ring Address Resolution)
66
6
78
6
This node detects that the owner is down and claims the token
8
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 25
UC Berkeley WOW
Token Recovery (Ring Address Resolution)
66
6
78
88
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 26
UC Berkeley WOW
Token Recovery (Ring Address Resolution)
86
6
78
8
8
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 27
UC Berkeley WOW
QOS Interface
High Priority Applications (6) Low Priority Applications (6,3)
Wireless Token Ring Protocol (10)
Register 6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 28
UC Berkeley WOW
QOS Interface
High Priority Applications (6) Low Priority Applications (6,3)
Wireless Token Ring Protocol (4)
GrantedRegister 6
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 29
UC Berkeley WOW
QOS Interface
High Priority Applications (6) Low Priority Applications (6,3)
Wireless Token Ring Protocol (4)
Granted Handler Register 3
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 30
UC Berkeley WOW
QOS Interface
High Priority Applications (6) Low Priority Applications (6,3)
Wireless Token Ring Protocol (1)
Granted
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 31
UC Berkeley WOW
WTRP Deliverables (2001)
WTRPSoftwareCore
UDP CORE
UDP Implementation
IP
API
WTRPSoftwareCore
KERNEL CORE
LINUX KERNEL Implementation
IP
Driver
WTRPSoftwareCore
SIMULATOR CORE
SIMULATOR Implementation
Channel Model
Front End
http://wow.eecs.berkeley.edu
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 32
UC Berkeley WOWUDP: Video Streaming
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 33
UC Berkeley WOWSimulation Front End
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 34
UC Berkeley WOW
A
B
A
B
A
B
1 32
Token Rotation Time Vs. Rotation
C CC
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 35
UC Berkeley WOW
Fairness
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 36
UC Berkeley WOW
Throughput Comparison With 802.11 DCF
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 37
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 38
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 39
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 40
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 41
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 42
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.
July 15, 2002
SCI02 ORLANDO
Wireless Token Ring Protocol 43
UC Berkeley WOW
ConclusionsThe wireless token ring protocol (WTRP) is a medium access control protocol for wireless networks in mission critical systems.
It supports quality of service in terms of bounded latency and reserved bandwidth.
WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions.
It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time.
It is a distributed protocol that supports many topologies since not all stations need to be connected to each other or to a central station.
It can be used with an admission control agent for bandwidth or latency reservations.
WTRP is robust against single node failure. WTRP is designed to recover gracefully from multiple simultaneous faults.