1. Green Cellular Networks Based on Accumulation with Accumulative Broadcast Algorithms IEEE WCNC 2011 - Network Reporter: 黃得一

2. 2 Outline Introduction System Model  Accumulation  Radiation and Harmful Region  Packetization  SNR, Accumulation Rate and Accumulation Threshold  Virtual Tree (VT) Cellular Accumulation Broadcast Algorithm  Initialization  Power Level Determination  Updating Accumulation Rate & Virtual Tree  Reducing Power Level Simulation Conclusion

3. 3 Introduction This paper considers multi-hop cellular networks in which nodes use accumulation for cooperative broadcasting in order to save total energy with low delay. Our purpose is to build up Green Cellular Networks (GCN) which represent the trend of Next-Generation Networking (NGN) and we can focus on the power property. We also propose Virtual Tree (VT) to determine hop number in order to evaluate delay property of accumulative routing algorithms. Then, we propose a centralized broadcast routing algorithm specific for the asymmetric cellular based on accumulation named Cellular Accumulative Broadcast (CAB) Algorithm, which aims to realize low-delay minimum energy broadcast. Simulation results show that our CAB algorithm performs superior to other existing accumulative or non-accumulative broadcast algorithms, which means GCN built up with CAB could be cost-effective with low delay.

4. 4 System Model Accumulation Accumulation refers to energy accumulation or power accumulation. In the accumulation, the hardware of the communication entity (the destination node) bares the ability of receiving multiple broadcasting data streams containing the same information just above the accumulation power threshold almost at the same time or within a short period. Compared to the traditional receiving strategy that the node can only receive power above the correctly receiving power threshold. There are mainly three kinds of accumulation:  Accumulation in Time (AT)  Accumulation in Space (AS)  Accumulation in Space and Time (AST).

5. 5 Cont. Radiation and Harmful Region To reduce power is to reduce radiation. Packetization The preamble and the header could be easily obtained at the receiver Preamble: a sequence of pre-specified symbols for time synchronization Header: the packet duration and uncoded or easy-to-decode multicast group routing information computed by the base station in advance Payload: coded information Virtual Tree (VT) We have to propose Virtual Tree (VT) ahead specific for accumulative algorithms to measure the delay property via hop number hop number based on VT could actually reflect the delay

6. 6 Cont. SNR, Accumulation Rate and Accumulation Threshold SNR: Signal-to-Noise Ratio Accumulation threshold minimum SNR of receiving signal that signal that could be detected but not correctly obtained by the receiver. Correctly receiving threshold Accumulation rate When the kth node transmits a packet, the amount of reception by the lth node is quantified by the accumulation rate of the lth node defined as Where is accumulation rate function given by

7. 7 Notation used in Cellular Accumulative Broadcast Algorithm(CAB)

8. 8 CAB Algorithm: Initialization Initialization Get information of the set of all nodes (N) including BS and the link status (link) Prim’s algorithm to compute node-based MST 1.Initialized power levels (pl) and structure of MST named Original Tree (OT) 2.including the set of leaf nodes (leaf) and hop number for each node (hopmst).  Accumulation threshold at the receiver  Correctly receiving threshold  virtual tree set S to be empty  power level set for each node (plx) to be pl  x to be the sorting difference set of N and leaf  accumulation rat(Acc) and accumulation sources (accsrc) of others (N excluding BS ) to be zero and empty separately

9. 9 CAB Algorithm Power Level Determination Updating Accumulation Rate & Virtual Tree Reducing Power Level

10. 10 CAB Algorithm: Power Level Determination BS Node

11. 11 Cont. BS Node

12. 12 Cont. BS Node

13. 13 Cont. BS Node

14. 14 CAB Algorithm Power Level Determination Updating Accumulation Rate & Virtual Tree Reducing Power Level

15. 15 CAB Algorithm: Reduce BS Node

16. 16 CAB Algorithm: Updating Accumulation Rate & Virtual Tree BS Node

17. 17 Simulation

18. 18 Simulation

19. 19 Simulation

20. 20 Simulation

21. 21 Conclusion  We have made a description of accumulation to explain the advantages of accumulative broadcast over non-accumulative ones. Then, based on accumulation and for the increasing demand for energy saving and less radiation, we have proposed a centralized broadcast routing algorithm named Cellular Accumulative Broadcast Algorithm to build up Green Cellular Networks. Moreover, Virtual Tree is of great use in accumulative algorithms for both broadcast and unicast ones for the purpose of evaluating communication delay. In the future, we will focus on the accumulative unicast in cellular networks.

22. 22 每周一句  where the links’ values must be no less than M’s power level last updated so as to assure that the children could fall in the transmission range of M.  which nodes use accumulation for cooperative broadcasting in order to save total energy with low delay.  so as to = in order to 為了  in order to 可以放在句子的首部或中間的， 而 so as to 是一定要放在句子的中間的。