1. Converge-Cast: On the Capacity and Delay Tradeoffs Xinbing Wang Luoyi Fu Xiaohua Tian Qiuyu Peng Xiaoying Gan Hui Yu Jing Liu Department of Electronic EngineeringShanghai Jiao Tong University, China 6/5/2016 Congerve-Cast: On the Capacity Delay Tradeoffs 1

2. 2 Outline Introduction  Motivations  Objectives Models and Definitions Converge-Cast Capacity of Stationary Network Converge-Cast Capacity and Delay in MANET Conclusion and Future Work Congerve-Cast: On the Capacity Delay Tradeoffs 2

3. Motivation  Capacity of wireless ad hoc network is not scalable: in a static ad hoc wireless network with n nodes, the per-node capacity is ad hoc wireless network with n nodes, the per-node capacity is limited as. Interference is the main reason behind. limited as. Interference is the main reason behind.  Mobility is utilized to increase the network capacity to. Interference is localized. [1] P. Gupta and P. R. Kumar, “The capacity of wireless networks”, in IEEE Transaction on Information Theory, 2000. Congerve-Cast: On the Capacity Delay Tradeoffs 3 [2] M. Grossglauser and D. N. C. Tse, “Mobility increases the capacity of ad hoc wireless networks,” IEEE/ACM Transactions on Networking. 2002.

4. Congerve-Cast: On the Capacity Delay Tradeoffs 4 Motivation  Converge-cast traffic is of significant value and has drawn much attention recently. Monitoring & Alarming System [3] Monitoring & Alarming System [3] Wireless sensor Network [4] Wireless sensor Network [4] [3] P. Zhang, C. M. Sadler, S. A. Lyon, and M. Martonosi, “Hardware design experiences in zebranet,” in Proc. ACM SenSys 2004, NY, USA. [4] M. Zhao, M. Ma and Y. Yang, “Mobile data gathering with space-division multiple access in wireless sensor networks,” in Proc. IEEE INFOCOM 2008, Phoenix, Arizona, Apr. 2008.

5. Motivation  Converge-cast traffic pattern is a generalized version of unicast traffic and shares a similar configuration with multicast traffic [5] in that the information dissemination can both be modeled as a spanning tree. [5] Xiang-Yang Li, “Multicast Capacity of Wireless Ad Hoc Networks”, in IEEE/ACM Transaction on Networking, January, 2008. Congerve-Cast: On the Capacity Delay Tradeoffs 5

6. 6 Objective  Both unicast and multicast capacity have been extensively studied in static & mobile ad hoc network.  There has been few works dealing with converge-cast network. What are the congverge-cast capacity and delay in stationary and mobile ad hoc network? What are the congverge-cast capacity and delay in stationary and mobile ad hoc network?

7. 7 Outline Introduction Models and Definitions  Stationary network  Mobile network Converge-Cast Capacity of Stationary Network Converge-Cast Capacity and Delay in MANET Conclusion and Future Work Congerve-Cast: On the Capacity Delay Tradeoffs 7

8. 8 Stationary Network  n nodes are randomly distributed in the unit square and remain static.  A Common transmission range is adopted by all the nodes to guarantee network connectivity.  For each converge-cast session, k sources and 1 destination are randomly selected from the n nodes. There are n sessions existed in the network.

9. Congerve-Cast: On the Capacity Delay Tradeoffs 9 Stationary Network  The network model is similar to the that of multicast network. The only difference is that the multicast spanning tree is reversed. Multicast Spanning Tree Converge-cast Spanning Tree

10. Congerve-Cast: On the Capacity Delay Tradeoffs 10 Stationary Network  Transmission Protocol: Protocol Model Definition: Let denote the distance between node i and node j, and the common transmission range, then a transmission from i to j is successful if for any other node k transmitting simultaneously. Heterogeneity Increases Multicast Capacity in Clustered Network 10

11. Congerve-Cast: On the Capacity Delay Tradeoffs 11 Mobile Network  n nodes are moving according to an independent identically distributed mobility model.  Cell partitioned model is assumed to model the interference, which is identical to [6].  For each converge-cast session, k sources and 1 destination are randomly selected from the n nodes. There are n sessions existed in the network. (identical to stationary network) [6] M. J. Neely, and E. Modiano, “Capaicty and delay tradeoffs for ad hoc mobile networks,” IEEE Transactions on InformationTheory, vol. 51, no. 6, pp. 1917-1937, Jun. 2005.

12. Congerve-Cast: On the Capacity Delay Tradeoffs 12 Mobile Network  Mobility Model: independent identically distributed model A simplified mobility model A simplified mobility model Mathematical Tractability Mathematical Tractability Give an upper bound of the theoretical result Give an upper bound of the theoretical result

13. Congerve-Cast: On the Capacity Delay Tradeoffs 13  Transmission Protocol: Cell partitioned network Nodes in the same cell are permitted to communicate Nodes in the same cell are permitted to communicate 9-TDMA is assumed to avoid inter-cell interference 9-TDMA is assumed to avoid inter-cell interference Mobile Network

14. Congerve-Cast: On the Capacity Delay Tradeoffs 14 Congerve-Cast: On the Capacity Delay Tradeoffs 14 Mobile Network  The traffic pattern is also similar to the that of multicast network. The only difference is that the information is sent from k mobiles to the common destination.

15. Congerve-Cast: On the Capacity Delay Tradeoffs 15 Mobile Network  Sending Pool: packets that are sampled by the node itself. When a new session starts, a new packet is produced and duplicated m times if the node is selected as source.  Relaying pool: packets that are sampled by other node and will be sent to other destinations. When this node meets another node which is the destination of one of the packets P in the relaying pool, the packet P will be delivered to the receiving pool.  Receiving pool: packets that are designated for itself. When this node meets another node which contains a packet P, the packet P will be delivered to the receiving pool in this node.

16. Congerve-Cast: On the Capacity Delay Tradeoffs 16 Introduction Models and Definitions Converge-Cast Capacity of Stationary Network Converge-Cast Capacity and Delay in MANET Conclusion and Future Work

17. Congerve-Cast: On the Capacity Delay Tradeoffs 17 Capacity of Stationary Network  Delay is usually not considered in static network because it only relates with the number of hops.  An efficient way to estimate the upper bound in static converge- cast networks is to study its redundancy under the pattern. Theorem 5.1: The total capacity for random stationary ad hoc network with one-hop strategy is with per-node throughput.

18. Congerve-Cast: On the Capacity Delay Tradeoffs 18 Capacity of Stationary Network  Relays are necessary according to protocol model, yet Theorem 5.1 only shows the capacity of static ad hoc network with no relays. Then the whole transmission route can be treated as a chain whose length can be treated as redundancy because the whole transmission utilizes the same number of transmissions.  For unicast, the average redundancy is,then the total capacity is ; For multicast, the average number of edges of the spanning tree is, then the total capacity is, then the total capacity is  For Converge-cast network, we get the same result as unicast network, so the total capacity is identical to unicast network.

19. Congerve-Cast: On the Capacity Delay Tradeoffs 19 Congerve-Cast: On the Capacity Delay Tradeoffs 19 Introduction Models and Definitions Converge-Cast Capacity of Stationary Network Converge-Cast Capacity and Delay in MANET  Delay of Single Session in MANET  Delay and Capacity of Multi-session in MANET Conclusion and Future Work

20. Congerve-Cast: On the Capacity Delay Tradeoffs 20 Delay of Single Session in MANET  In mobile ad hoc network, delay should be taken into consideration and it deals with both routing scheme and mobility pattern.  The delay consists of two types of delays: transmission delay and queuing delay. However, transmission delay can be ignored since there are at most 2 hops in this model and such assumption does not change the order of the result.  The total delay is defined as the maximum of k delays:

21. Congerve-Cast: On the Capacity Delay Tradeoffs 21 Delay of Single Session in MANET  Delay estimation of 1-hop algorithm Only source-destination transmission is allowed. Only source-destination transmission is allowed.  Delay estimation of 2-hop algorithm Both source-relay and relay-destination transmission are allowed and taken into consideration. Both source-relay and relay-destination transmission are allowed and taken into consideration.

22. Congerve-Cast: On the Capacity Delay Tradeoffs 22 Capacity Delay of Multi-Session  Case I: without redundancy The delay is the same as the 1-hop algorithm The delay is the same as the 1-hop algorithm It does not improve the delay and capacity in ad hoc networks. It does not improve the delay and capacity in ad hoc networks. The per-node capacity is, which is identical to unicast network in MANET. The per-node capacity is, which is identical to unicast network in MANET.

23. Congerve-Cast: On the Capacity Delay Tradeoffs 23 Capacity Delay of Multi-Session  Case II: with redundancy The delay is the same as the 2-hop algorithm The delay is the same as the 2-hop algorithm delay and capacity tradeoff is improved in ad hoc networks. delay and capacity tradeoff is improved in ad hoc networks. We obtain an optimal per-node capacity and delay tradeoff as follows: We obtain an optimal per-node capacity and delay tradeoff as follows:

24. Congerve-Cast: On the Capacity Delay Tradeoffs 24 Congerve-Cast: On the Capacity Delay Tradeoffs 24 Introduction Models and Definitions Converge-Cast Capacity of Stationary Network Converge-Cast Capacity and Delay in MANET Conclusion and Future Work

25. Congerve-Cast: On the Capacity Delay Tradeoffs 25 Conclusion  For stationary network, we find that the achievable capacity is the same as the unicast case. The comparison is as follows:  For mobile network, we derive the capacity and delay with and without redundancy. The comparison is as follows:

26. Congerve-Cast: On the Capacity Delay Tradeoffs 26 Conclusion  We make a comparison among the unicast, multicast, converge- cast capacity delay tradeoffs of both stationary and mobile ad hoc network.

27. Congerve-Cast: On the Capacity Delay Tradeoffs 27 Conclusion  The impact of base station is investigated in both unicast and multicast network. However, it is still unknown whether it can improve the performance in converge-cast network.  We assume a fast mobility model in this work, which means the time scale of node moving is identical to the time slot for data transmission. When the node speed is not that fast, multihop transmission is allowed.  In this work, we only consider i.i.d mobility pattern, which is unreal for the real world. We can also investigate the capacity under some more practical mobility model, e.g. random walk, random way point mobility models.

28. 6/5/2016 Congerve-Cast: On the Capacity Delay Tradeoffs 28 Thank you for listening