ICMA: AN EFFICIENT INTEGRATED CONGESTION CONTROL APPROACH

Background: With the growing popularity of various group communication applications such as file transfer, multimedia events, distance learning, email distribution, multiparty video conferencing and teleconferencing, multicasting seems to be a useful tool for efficient multipoint data distribution. An efficient communication technique depends on the various parameters like processing speed, buffer storage, and amount of data flow between the nodes. If data exceeds beyond the capacity of a link or node, then it introduces congestion in the network. A series of multicast congestion control algorithms have been developed, but due to the heterogeneous network environment, these approaches do not respond nor reduce congestion quickly whenever network behavior changes. Objective: Multicasting is a robust and efficient one-to-many (1: M) group transmission (communication) technique to reduced communication cost, bandwidth consumption, processing time and delays with similar reliability (dependability) as of regular unicast. This patent presents a novel and comprehensive congestion control method known as integrated multicast congestion control approach (ICMA) to reduce packet loss. Methods: The proposed mechanism is based on leave-join and flow control mechanism along with proportional integrated and derivate (PID) controller to reduce packet loss, depending on the congestion status. In the proposed approach, Proportional integrated and derivate controller computes expected incoming rate at each router and feedback this rate to upstream routers of the multicast network to stabilize their local buffer occupancy. Results: Simulation results on NS-2 exhibit the immense performance of the proposed approach in terms of delay, throughput, bandwidth utilization, and packet loss than other existing methods. Conclusion: The proposed congestion control scheme provides better bandwidth utilization and throughput than other existing approaches. Moreover, we have discussed existing congestion control schemes with their research gaps. In the future, we are planning to explore the fairness and quality of service issue in multicast communication.

Broadband Fiber Optical Access

We are currently witnessing an unprecedented growth in bandwidth demand, mainly driven by the development of advanced broadband multimedia applications, including video-on-demand (VoD), interactive highdefinition digital television (HDTV) and related digital content, multiparty video-conferencing, and so forth. These Internet-based services require an underlying network infrastructure that is capable of supporting high-speed data transmission rates; hence, standards bodies and telecom providers are currently focusing on developing and defining new network infrastructures that will constitute future-proof solutions in terms of the anticipated growth in bandwidth demand, but at the same time be economically viable. Most users currently enjoy relatively high speed communication services through digital subscriber line (DSL) access technologies, but these are widely seen as short-term solutions, since the aging copper-based infrastructure is rapidly approaching its fundamental speed limits. In contrast, fiber optics-based technologies offer tremendously higher bandwidth, a fact that has long been recognized by all telecom providers, which have upgraded their core (backbone) networks to optical technologies. As Figure 1 shows, the current network landscape thus broadly comprises of an ultrafast fiber optic backbone to which users connect through conventional, telephone grade copper wires. It is evident that these copper-based access networks create a bottleneck in terms of bandwidth and service provision. In Figure 1, a splitter is used to separate the voice and data signals, both at the user end and at the network operator’s premises. All data leaving from the user travel first through an electrical link over telephonegrade wires to the operator local exchange. They are then routed to an Internet service provider (ISP) and eventually to the Internet through fiber-optic links. In contrast to the access scheme depicted in Figure 1, fiber-to-the-home (FTTH) architectures are novel optical access architectures in which communication occurs via optical fibers extending all the way from the telecom operator premises to the customer’s home or office, thus replacing the need for data transfer over telephone wires. Optical access networks can offer a solution to the access network bottleneck problem, and promises extremely high bandwidth to the end user, as well as future-proofing the operator’s investment (Green 2006; Prat, Balaquer, Gene, Diaz, & Fiquerola, 2002). While the cost of FTTH deployment has been prohibitively high in the past, this has been falling steadily, and FTTH is now likely to be the dominant broadband access technology within the next decade (Green, 2006).