Efficient Broadcast Disks Program Construction in Asymmetric Communication Environments

ABSTRACT A well-known technique for broadcast program construction is the Broadcast Disks. However, it has important disadvantages, as for example that the broadcast program construction procedure leaves some parts of the broadcast program empty. This paper proposes a new approach for the construction of the broadcast program. Specifically, it presents three new algorithms, which face the problems of the Broadcast Disk Technique. According to our approach, the broadcast program is constructed with the minimum possible length, respecting the selected disk relative frequencies and keeps the average delays of retrieving data-items low. The constructed broadcast programs have no empty parts and retain their desired properties in any combination of disk relative frequencies. Experimental results show that this approach is more efficient than Broadcast Disks in all cases

ON PERFORMANCE IMPROVEMENT OF WIRELESS PUSH SYSTEMS VIA SMART ANTENNAS

In wireless telecommunication, the network consists of a broadcast server with a set of clients. It sends a group of information to the clients in a desired closed loop path. According to the information send by the broadcasting server the clients access it this should be happen in a cyclic path. In olden days we use fixed directional antennas for transmitting the signal from one place to another. Due to some drawback over the existing one we use multiple directional antennas at the Broadcast Server has been shown to increase performance. In many cases however, such broadcasting systems fail to exploit the full potential of the multiple antennas as they do not take into account the geographical distribution of clients within the coverage area of the system. This letter proposes an adaptive smart antenna based wireless push system where the beam width of each smart antenna is altered based on the current placement of clients within the system area. Coupled with a modification of the broadcast schedule, the proposed approach significantly increases the performance observed by the system clients

Priority-Oriented Adaptive Control With QoS Guarantee for Wireless LANs.

In today’s wireless networks there is a great need for QoS, because of the time-bounded voice, audio and video traffic. A new QoS enhanced standard is being standardized by the IEEE 802.11e workgroup. It uses a contention free access mechanism called Hybrid Control Channel Access (HCCA) to guarantee QoS. However, HCCA is not efficient for all types of time-bounded traffic. This work proposes an alternative protocol which could be adapted in HCF (Hybrid Coordination Function). The Priority Oriented Adaptive Control with QoS Guarantee (POAC-QG) is a complete centralized channel access mechanism, it is able to guarantee QoS for all types of multimedia network applications, it enhances the parameterized traffic with priorities, and it supports time division access using slots. Furthermore, it instantly negotiates the quality levels of the traffic streams according to their priorities, supporting multiple streams to the best quality it can achieve. POAC-QG compared to HCCA, provides higher channel utilization, adapts better to the characteristics of the different traffic types, differentiates the traffic streams more efficiently using priorities, and generally exhibits superior performance