Fast power-up active link protection in autonomous distributed transmitter power control

Abstract

In this work, we propose an enhancement to the DPC/ALP (Distributed Power Control with Active Link Protection) algorithm that allows fast power ramp-up without compromising the ALP guarantee. The original DPC algorithm was first augmented with ALP to provide absolute performance guarantees. The basis of Active Link Protection lies on constraining the rate of the new links' transmission power increase during the admission process, inducing a trade-off between the duration of the admission process and the network capacity reserved for absorbing the SINR fluctuations. Thus, to minimize the capacity loss, power-up should be slow, prolonging admission delay. In the new scheme, the power-up is accelerated when congestion is low, via test transmissions. Specifically, pairs of mini slots are interleaved between payload-carrying slots. In the first minislot, a link has the opportunity to carry out a test transmission in the wireless channel at an arbitrarily high power level, greater than what DPC/ALP allows. The purpose of this test transmission is to communicate the desired transmission power to the other links in the network neighborhood. The latter respond in the second mini-slot, indicating their distress if the first mini-slot transmissions generated excessive interference to their receivers. The absence of transmission at the second mini-slot signifies that no link has opposed, thus the link is free to use the first mini-slot's high power level in their subsequent slots, realizing the fast power ramp up. In contrast, if a transmission is sensed in the second mini-slot (emanating from one or more links in distress-typical under network congestion, when links are closely packed), the power ramp up will revert to the standard increase of DPC/ALP. © 2008 IEEE.