IEEE 802.11 DCF 通訊協定應用在AdHoc網路 下使用許多不同的連線路徑尋找方法（AODV、ADV、DSDV、DSR、GOD），所有移動節點(Mobile Node，簡稱MN)為了維持路徑和傳輸資料都是以最大的傳輸功率。802.11 DCF大多的電力消耗都是在傳輸資料封包上，且傳送端在傳輸資料以最大的傳輸功率傳送，因此可能與鄰近節點發生封包碰撞，而造成MN需要重新傳送封包，導致MN可傳輸資料量下降。
本論文提出在AdHoc網路下使用傳送功率動態調整演算法，使用上次傳送的資料功率和每次傳送時通道NOISE的變化量，來計算這次傳送的資料功率，使功率可以維持路徑的穩定，來建立點對點(peer to peer)連線並傳送資料，進而有效控制資料封包功率，來降低電力的消耗和減少封包碰撞。本研究利用NCTUNS模擬軟體，模擬MN移動性(Mobility)快慢和傳送接收對數量多寡的情況下，觀察採用動態傳送功率演算法的網路輸出值，端點對端點延遲時間（End-to-end Delay）和封包遺失率（Packet Lost Rate）。而採用動態傳送功率演算法的MN，其網路輸出值、端點對端點延遲時間和封包遺失率都比使用傳統802.11 DCF協定的MN，效能都有些微的提昇。

The Nodes of Ad Hoc network may run in a noisy environment. This will degrade the quality of the channel. When the level of noise is increased, the throughput of the network will be decreased. Since the nodes in Ad Hoc network use IEEE 802.11 DCF protocol and send frames with max power, the interference from other nodes will create noisy environment and the throughput will be decreased and collision probability will be increased.

In this paper, we present a protocol named Transmission Power Dynamic Adjust Algorithms (TPDAA) for Ad Hoc network. When a node needs to sends data, its MAC layer calculates the changed noise level of the past. In this way, the sender can calculate the needed power level under present noise level. The collision probability will be decreased and SNR of channel will be more stable under this scheme. For a specific routing protocol, a node can adjust the number of neighbors with this power control scheme and achieve better performance for Ad Hoc network.

[1] IEEE Working Group, Part 11：Wireless LAN Medium Access Control (MAC)and Physical Layer (PHY) specifications , IEEE Standard 802.11, 1999.
[2] IEEE Working Group, Part 11：Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: High-speed Physical Layer in the5Ghz band , IEEE Standard 802.11a, 1999.
[3] IEEE Working Group, Part 11：Wireless LAN medium access control (MAC) and Physical layer (PHY) specifications：High-speed physical layer extension in the 2.4 GHz band, IEEE Standard 802.11b , Sept. 1999.
[4] IEEE Working Group, Part 11：Wireless LAN Medium Access Control (MAC)and Physical Layer (PHY) specifications: Amendment 4：Further Higher Data Rate Extension in the 2.4 GHz Band, IEEE Standard 802.11g , 2003.
[5] IEEE 802.11 Working Group, Part 11：Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications：Amendment 8：Medium Access Control (MAC) Quality of Service Enhancements, IEEE Standard 802.11e, Sept. 2005.
[6] Vincent Vermeer Lucent Technologies. Wireless LANs：Why IEEE 802.11DSSS. IEEE Conference ,pp.172–178, Nov. 1997.
[7] D-Link 技術團隊，無線區域網路技術白皮書，第7-5 頁，台灣，松崗，民國九十五年。

[8] Haitao Wu1, Yong Peng1, Keping Long1, Shiduan Cheng1, Jian Ma2. Performance of Reliable Transport Protocol over IEEE 802.11 Wireless LAN:Analysis and Enhancement. IEEE INFOCOM,pp.599-600, Jun. 2002
[9] D-Link 技術團隊，無線區域網路技術白皮書，第7-20-7-25 頁，台灣，松崗，民國九十五年。
[10] Gomez, J., Campbell, A.T., Naghshineh, M., Bisdikian, C. . Conserving Transmission Power In Wireless Ad Hoc Networks . International Conference on Network Protocols,pp.24-34, Nov. 2001.
[11] Jung, E.-S., Vaidya, N.H. . A Power Control MAC Protocol For Ad Hoc Networks. International Conference on Mobile Computing and Networking, pp.36-47,Sep.2002.
[12] Xiao, M., Lu, F., Zhang, J., Yang, G. . A New Power-Controlled MAC for Ad Hoc Networks. International Conference on Wireless Communications, pp.1722-1725, Sep.2007.
[13] Jing, X., Mau, S.-C., Raychaudhuri, D., Matyas, R. . Reactive Cognitive Radio Algorithms for Co-Existence between IEEE 802.11b and 802.16a Networks. Global Telecommunications Conference ,pp.2465-2469,Sep.2005.
[14] S.Y. Wang, C.L. Chou, C.H. Huang, C.C. Hwang, Z.M. Yang, C.C. Chiou,
and C.C. Lin. The Design and Implementation of the NCTUns 1.0 Network
Simulato. Computer Networks,Vol. 42,Issue 2,pp.175-197, Jun. 2003.