Considering traditional MAC protocols for Wireless Sensor Networks cannot provide service differentiation for different traffic classes, we propose a Self-adaption QoS-aware MAC protocol (SQ-MAC). The protocol can provide collision-free time slots for nodes, and take different contention window size for different traffic classes. It can also introduce virtual multiqueue and relatively fair sche...

This paper describes the designs of a saturating adder, multiplier, single MAC unit, and dual MAC unit with one cycle latencies. The dual MAC unit can perform two saturating MAC operations in parallel and accumulate the results with saturation. Specialized saturation logic ensures that the output of the dual MAC unit is identical to the result of the operations performed serially with saturatio...

The Mobile adhoc network (MANET), is a collection of mobile wireless nodes that self-organize without the aid of centralized control or any preexisting infrastructure. This paper presents the effect of MAC protocols (MAC 802.11, MAC/TDMA) on various routing protocols in order to choose the best routing protocol and MAC protocol to enhance the performance. The simulation compared three adhoc rou...

This paper reviews medium access control (MAC), an enabling technology in wireless sensor networks. MAC protocols control how sensors access a shared radio channel to communicate with neighbors. Battery-powered wireless sensor networks with many nearby nodes challenge traditional MAC design. This paper discusses design trade-offs with an emphasis on energy efficiency. It classifies existing MAC...

In this article we present RNET MAC a novel MAC protocol to be used in wireless ATM (WATM) environments. The MAC protocol features a distributed control for media access. Therefore RNET MAC ts well for spontaneous network setups and frequent network con guration changes. We discuss some design options and show basic performance results of RNET MAC in di erent network scenarios such as fully mes...

We discuss the security of Message Authentication Code (MAC) schemes from the viewpoint of differential attack, and propose an attack that is effective against DES-MAC and FEAL-MAC. The attack derives the secret authentication key in the chosen plaintext scenario. For example, DES(8-round)-MAC can be broken with 2 pairs of plaintext, while FEAL8-MAC can be broken with 2 pairs. The proposed atta...

In this article we present RNET MAC-a novel MAC protocol to be used in wireless ATM (WATM) environments. The MAC protocol features a distributed control for media access. Therefore RNET MAC ts well for spontaneous network setups and frequent network connguration changes. We discuss some design options and show basic performance results of RNET MAC in diierent network scenarios such as fully mes...

BACKGROUND In allograft rejection, recipient leukocytes and alloantibodies first target donor endothelial cells. Although the leukocyte integrin Mac-1 (alpha(Mbeta2), CD11b/CD18) facilitates cell-cell interactions among leukocytes and interactions between leukocytes and endothelial cells or platelets, its role in allograft survival and vasculopathy is incompletely defined. METHODS AND RESULTS...