, Slide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Reliable Broadcast for WBAN] Date Submitted: [September, 2008] Source: [Sungrae Cho, Wonsuk Choi, Xiangbo Zhang, Laihyuk Park and Dong Dong] [School of Computer Science and Engineering, Chung-Ang University ] Address [221 Heukseok, Dongjak, Seoul , Republic of Korea] Voice:[ ], FAX: [ ], Re: [Contribution to IEEE Meeting, September 2008] Abstract:[This document is a summary of the proposed Timer-based Reliable Broadcast (TRB) for WBAN networks.] Purpose:[Contribution] Notice:This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P doc.: IEEE

Reliable Broadcast for WBAN Slide 2, UC UC LAB Chung-Ang University Sungrae Cho, Wonsuk Choi, Xiangbo Zhang, Laihyuk Park, and Dong Dong doc.: IEEE

Why reliable broadcast is needed? –Sometimes medical emergency event occurs in WBAN and needs to be broadcast to entire network reliably. –Some control information needs to be delivered to entire network reliably. –S/W update needs to be done reliably Introduction Slide 3, doc.: IEEE

Simple Flooding: it starts with a source node broadcasting a frame to all neighbors. Each of neighbors in turn forwards the frame to all its neighbors exactly one time and this continues until all reachable network nodes have received the frame. NAK-based: receivers respond with only negative acknowledgments. ACK-based: more reliable scheme where the transmitter waits for all ACKs from the receivers until it transmits the next frame Different Reliable Broadcast Schemes Slide 4, doc.: IEEE

Suppose that every receiver node acknowledges for broadcast data, e.g., The broadcast node will be overwhelmed by acknowledge messages (a.k.a. implosion problem). This acknowledgments are generated almost simultaneously if no control enforced. MOTIVATION (1/2 MOTIVATION (1/2) Slide 5, doc.: IEEE

This implosion problem also causes the problems of –Unnecessary Collision –Unnecessary Power Consumption Solution: randomize the transmission of the ACKs How?: –Use timers –Implicit ACK (reduce the # of acks) MOTIVATION (2/2 MOTIVATION (2/2) Slide 6, doc.: IEEE

Transmitter Behavior –Transmitter broadcasts data and waits for. –Transmitter maintains a Bit Map indicating whether it received an ACK from a particular one-hop neighbor. –If the Bit Maps are all set (Tx received all ACKs) before expires, the transmitter broadcasts the next data. –If any of the Bit Maps are not set after expires, the transmitter rebroadcasts the data. TRB (Timer based Reliable Broadcast) Slide 7, doc.: IEEE

Receiver Behavior (after receiving broadcast data) –On successful receipt of broadcast data, each receiver acts as a transmitter by broadcasting the data using random timer D R. –This timer randomizes transmission of the received broadcast data. –One of the transmissions is considered to be an implicit ACK to the original broadcaster. TRB (Timer based Reliable Broadcast) Slide 8, doc.: IEEE

8 1 broadcast coordinator Slide 9, TRB (Timer based Reliable Broadcast) doc.: IEEE

coordinator broadcast Implicitly considered as anACK 8 Slide 10, TRB (Timer based Reliable Broadcast) doc.: IEEE

coordinator ACK Slide 11, TRB (Timer based Reliable Broadcast) doc.: IEEE

Collision Coordinator ACK Slide 12, TRB (Timer based Reliable Broadcast) doc.: IEEE

coordinator broadcast Random timer Slide 13, TRB (Timer based Reliable Broadcast) doc.: IEEE

Simulations Setup Results nodes nodes nodes nodes nodes Performance Evaluation (1) Slide 14, doc.: IEEE

Simulation platform: NS2 + LR-WPAN # of nodes: Variable Neighbor distance: 7 m ~ 11m Tx range: 12 m PAN Coordinator (PC): bottom node (or designated node) Network startup: –PC starts at: 0.0 –Any other node starts at: random time between 1.0 and 3.0 Frame error rate : 10% Experimental setup Performance Evaluation (2) Slide 15, doc.: IEEE

Successfully received nodes (%):Successfully received nodes (%): we collected # of nodes that received the frame successfully per each frame. Then, the percent of successfully received nodes is calculated as the ratio of # of successfully received nodes to entire # of nodes. Energy consumption:Energy consumption: average # of transmissions of a frame as an energy budget. Measured Performance Evaluation (3) Slide 16, doc.: IEEE

10 nodes : Reliable Broadcasting PAN Coordinator Node having asso ciated and being coordinator Node having associ ated and being leaf node 25 [18] Parent ID Node ID Performance Evaluation (4) Slide 17, doc.: IEEE

20 nodes : Reliable Broadcasting PAN Coordinator Node having asso ciated and being coordinator Node having associ ated and being leaf node 25 [18] Parent ID Node ID Performance Evaluation (5) Slide 18, doc.: IEEE

30 nodes : Reliable Broadcasting PAN Coordinator Node having associated and being coordinator Node having associated and being leaf node 25 [18] Parent ID Node ID Performance Evaluation (6) Slide 19, doc.: IEEE

40 nodes : Reliable Broadcasting PAN Coordinator Node having associated and being coordinator Node having associated and being leaf node 25 [18] Parent ID Node ID Performance Evaluation (7) Slide 20, doc.: IEEE

50 nodes : Reliable Broadcasting PAN Coordinator Node having associated and being coordinator Node having associated and being leaf node 25 [18] Parent ID Node ID Performance Evaluation (8) Slide 21, doc.: IEEE

Successfully received nodes (%) Slide 22, doc.: IEEE

Energy Consumption Slide 23, doc.: IEEE

This work has been supported by HNRC of IITA. Slide 24, doc.: IEEE

Thank You! Slide 25, doc.: IEEE