TY - GEN
T1 - Minimal CDMA recoding strategies in power-controlled ad-hoc wireless networks
AU - Gupta, I.
N1 - This work was partially funded by DARPA/RADC grant F30602-99-1-6532 and NSF grant No. EIA 97-03470.
PY - 2001
Y1 - 2001
N2 - The problem of Code Division Multiple Access (CDMA) code assignment to eliminate primary and hidden collisions in multihop packet radio networks has been widely researched in the past. However, very little work has been done on the very realistic distributed, dynamic version of the CDMA transmitter-oriented code assignment (TOCA) problem in an ad-hoc network. None of the existing dynamic TOCA CDMA algorithms in literature are efficient, in terms of maximum code index assigned in the network, or number of times a mobile has to change its code. We present a set of local, distributed recoding strategies for the TOCA CDMA problem in an ad-hoc network where mobiles can arbitrarily 1) connect and disconnect, 2) move about, and 3) increase or decrease their transmission power - all these may need some mobiles to be recoded, to avoid new collisions. Our strategies, unlike those proposed earlier in literature, guarantee minimal recoding, that is, given a current network-wide code assignment and one of the above events, our strategies change the codes of the minimum number of mobiles needed to eliminate all collisions. Minimal recoding can be very important in reducing the effect of frequent code changes on the performance and criticality of distributed applications. Performance results that evaluate our dynamic minimal strategies are also presented.
AB - The problem of Code Division Multiple Access (CDMA) code assignment to eliminate primary and hidden collisions in multihop packet radio networks has been widely researched in the past. However, very little work has been done on the very realistic distributed, dynamic version of the CDMA transmitter-oriented code assignment (TOCA) problem in an ad-hoc network. None of the existing dynamic TOCA CDMA algorithms in literature are efficient, in terms of maximum code index assigned in the network, or number of times a mobile has to change its code. We present a set of local, distributed recoding strategies for the TOCA CDMA problem in an ad-hoc network where mobiles can arbitrarily 1) connect and disconnect, 2) move about, and 3) increase or decrease their transmission power - all these may need some mobiles to be recoded, to avoid new collisions. Our strategies, unlike those proposed earlier in literature, guarantee minimal recoding, that is, given a current network-wide code assignment and one of the above events, our strategies change the codes of the minimum number of mobiles needed to eliminate all collisions. Minimal recoding can be very important in reducing the effect of frequent code changes on the performance and criticality of distributed applications. Performance results that evaluate our dynamic minimal strategies are also presented.
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U2 - 10.1109/IPDPS.2001.925193
DO - 10.1109/IPDPS.2001.925193
M3 - Conference contribution
AN - SCOPUS:42549170907
T3 - Proceedings - 15th International Parallel and Distributed Processing Symposium, IPDPS 2001
SP - 1977
EP - 1984
BT - Proceedings - 15th International Parallel and Distributed Processing Symposium, IPDPS 2001
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 15th International Parallel and Distributed Processing Symposium, IPDPS 2001
Y2 - 23 April 2001 through 27 April 2001
ER -