1. KING FAHD UNIVIRSITY OF PETROLEUM AND MIERALS ELECTRICAL ENGINEERING DEPARTMENT MAC Protocols in ad hoc networks Rami Bakhsh 200319130 Mohammed Al-Farsi 200164630 References: http://www.moeforum.net Mobile Ad Hoc Networks by Faisal Aslam and Chia Ching Ooi Ad Hoc Wireless Media Access Protocols by Mikko Raatikainen

2.  Introduction  MAC Layer In Ad hoc network  MAC Protocols  Hidden Terminal Problem  Exposed Terminal Problem  MACA Protocol  Conclusions

3. Definition of the ad hoc network Consists of mobile nodes which communicate with each other through wireless medium without any fixed Infrastructure. http://www.moeforum.net

4. Important Features of ad hoc networks The network topology Every nodes may be mobile node Limited power Limited wireless bandwidth The channel quality is varibale No centralized units

5. MAC Layer In Ad hoc network MAC Layer: For sharing a single broadcast medium among multiple users. Concerned with per-link connections. Error detection and correction by using Cyclic redundancy checks, Parity schemes. Flow control. There are two types of MAC : Static MAC Dynamic MAC

6. MAC Static MAC TDMAFDMACDMAWDMA Dynamic MAC Scheduling Random Access Pure ALOHA Slotted ALOHA CSMA CSMA/CD Collision resolution MACA BI-MCMAC

7. Hidden Terminal Problem Two nodes transmit concurrently data to the same receiver => collision Use RTS and CTS control packets. ABC Mobile Ad Hoc Networks by Faisal Aslam and Chia Ching Ooi

8. Exposed Terminal Problem overhearing data transmission from neighboring nodes. ABCD Mobile Ad Hoc Networks by Faisal Aslam and Chia Ching Ooi

9. MACA Protocol Inspired by the CSMA/CA method ‌Extension to the CA part of the CSMA/CA Lack of carrier doesn’t always mean it’s OK to transmit ‌Presence of carrier doesn’t always mean it’s bad to transmit.

10. MACA and Hidden & Exposed Terminals Problems Ad Hoc MAC Protocol (Pusan)

11. Improvements of MACA Protocol MACA (1990) No carrier sensing. MACAW (1994) MACA with Wireless networks. Includes ACK for the fast error recovery. FAMA (1995) RTS-CTS exchange with non-persistent Carrier Sensing. MACA-BI (1997) Receiver initiative two-way handshake: RTR-Data.

12. Different kinds of MAC protocols for different problems. There are new protocols inspired