Presentation Transcript

1. WiSense Seminar Series

   Urgency-based MAC Protocol for WSBANs

   Presented by: Dr. Khaled A. Ali
2. Outline Introduction Wireless Personal Area Networks WSBAN Application Examples IEEE 802.15.4 MAC Protocol Urgency-based MAC Protocol for WSBANs U-MAC Performance Evaluation and Results Concluding Remarks
3. Introduction Massive deployment of Sensor Networks Stimulated by numerous industry segments, and government organizations Sensors and RFID tags will begin to inhabit every object Emergence of smart sensors with local intelligence Traffic volume increases dramatically Significant architectural changes to global IT infrastructure is expected Process moves to network edge to aggregate and filter traffic Directional shift in network traffic
4. Introduction Integration of WSNs into 4G Networks Evolution of current ITU and IEEE standards Connect sensor world with back-end computing environments Enable end-to-end solutions Mixed Network Traffic of different priority levels and different bandwidth requirements Other networks 2G network IP Network Phone network 3G network 4G network Cellular Net Sensor Net
5. Wireless Personal Area Networks WPAN (General Description): Low-rate:(250 kb/s, 40 kb/s and 20 kb/s data rates) Range: 10-20 meters Low power consumption Addresses: short 16-bit or long 64-bit Channels: 16 channels (2450 MHz band) , 10 channels (915 MHz band ) and 1 channel (868 MHz band) Access mechanisms:CSMA/CA or Aloha Reliability : Fully acknowledgement, error checking Cost: Low cost of deployment MAC& PHY: IEEE 802.15.4 and IEEE 802.15.4a
6. Wireless Personal Area Networks WPAN (Network Topology): peer-to-peer topology star topology FFD (PAN) RFD
7. Wireless Personal Area Networks WPAN (Layered Architecture): Upper Layers 802.2 LLC SSCS MAC PHY Physical Medium
8. WSBAN Application ExamplePersonal Health Care-mixed data rates Non-invasive WSBANs: Monitoring and sensing signals from the human body for medical applications Distributed communication over the human body Invasive (In-Body) WSBANs: Connect implanted medical devices (MICS band) and on-body sensors (ISM band) Miniature “Pill camera” Images and medical data are transmitted to a central WS View, edit, archive and e-mail the live video, images and date Physician can observe and detect exact location of suspected “in-body” disorder Patient data can be sent through the network to establish a diagnosis and trigger the required actions via actuators
9. WSBAN Application ExampleBusiness Meeting-mixed data rates RFID tag integrated in the watch allows entrance in the conference room Presentation can be downloaded from nodes in the room Business cards are exchanged by handshake Additional information can be displayed by video glasses Using microphone/motion sensors the main processing unit becomes aware of the meeting and automatically blocks phone calls
10. IEEE 802.15.4 MAC Protocol MAC Sublayer Generating Network beacons (PAN) Synchronization PAN association and disassociation CSMA-CA GTS INACTIVE CAP CFP(GTS) Beacon Beacon CAP- Contention Access Period CFP- Contention Free Period GTS- Guaranteed Time Slots
11. Urgency-based MAC Protocol for WSBANs Objectives: Supporting QoS in WSBANs for medical applications Increasing network throughput Minimizing packet rejection rate Minimizing power consumption Approach: Star network topology Controlling the number of packet retransmission High priority traffic contend more for the transmission medium than low priority traffic Slotted Aloha access mechanism
12. Urgency-based MAC Protocol for WSBANs Traffic Classification Critical Traffic Non-Critical Traffic Arrival Rate New Packet Arrival rate (λ) Critical packet arrival rate Non critical packet arrival rate Retransmitted packet arrival rate (λr) Retransmission Queues Success λ λ + λr Channel Collision C1 C2 C3 U-MAC Block diagram Cr
13. Urgency-based MAC Protocol for WSBANs Packet Transmission Scenario: Number of critical packet retransmission s; rc= 3 Number of non critical packet retransmissions ;rnc= 2 Pc rc rnc 3 2 2 1 1 0 Pnc
14. U-MAC Performance Evaluation and Results Beacon frame enabled Star network topology RFD nodes communicate with a single FFD RFD nodes composed of critical nodes and non critical nodes Critical nodes contend for the medium rc times Non critical nodes contend for the medium rnc times Maximum number of Critical Nodes Critical Nodes Packet Arrival Rate Network Throughput
15. U-MAC Performance Evaluation and Results Maximum Number of Critical Nodes Nc Aggrigate Packet Arrival rate G=1 Number of Critical Nodes
16. U-MAC Performance Evaluation and Results Maximum Number of Critical Nodes Nc (Cont.) Ntotal=20 G=1 λc=0.05, 0.06 λnc=0.015 rnc= 0, 2, 5 rc= 0- 5
17. U-MAC Performance Evaluation and Results Critical Packet Arrival Rate Ntotal=20, Nc=5 G=1 λnc=0.015 rnc= 0, 2, 5 rc= 0- 5
18. U-MAC Performance Evaluation and Results Network Throughput Critical Nodes Throughput Non Critical Nodes Throughput
19. U-MAC Performance Evaluation and Results Network Throughput (Cont.) Nc=10 Nnc=10 rnc=110000 time slots each of 1 sec. λc =λnc=0.025 λc =λnc=0.03
20. Concluding Remarks An Urgency-Based MAC protocol for WSBAN is proposed U-MAC protocol differentiates nodal medium access based of the criticality of the reported traffic Critical traffic is allowed to retransmit collided packets more than non critical traffic U-MAC protocol performance is evaluated mathematically and through simulation The performance results show the ability of the proposed protocol to differentiate network traffic
21. Thank you