Multi-carrier adaptive bandwidth control
As more and more wireless links are upgraded from TDM to packet technology, attention is focusing on how to further boost the capacity of packet-switched links. Moreover, network operators are keen on guaranteeing the quality of services they provide to their users and subscribers. Multi-carrier ABC technology further refines packet switching, providing operators with a way to utilize nearly 100% of available capacity.
Multi-carrier ABC technology optimizes the way traffic is distributed between multiple carriers over a single wireless link. In ABC, packets are further decomposed into bytes and each byte can be placed on any of the available carriers for transmission over the wireless link. At the receiving end of the link, ABC-aware equipment receives the bytes and re-constitutes the original packets.
ABC technology is always aware of the speed and congestion of each carrier at all times and distributes the bytes in the most optimal way for transmission given the current conditions of each carrier, for example congestion, current throughput rate, etc.
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Figure 4: Multi-carrier ABC traffic distribution using two carriers over a single wireless link.
With ABC, all carriers can be used for transmission at all times; there is no need for a dedicated backup carrier. If a carrier fails, it is simply bypassed and bytes are placed on the remaining carriers in the most optimal way given current conditions. If a failed carrier comes back into operation, it is immediately re-included in the ABC byte-distribution optimization scheme. If a carrier deteriorates due to weather conditions, ABC adjusts by sending fewer bytes over that carrier according to the degree of deterioration. With multi-carrier ABC, the wireless link’s capacity is optimized at all times and in all situations.
ABC for quality of service
In addition to maximizing capacity, multi-carrier ABC provides another significant benefit—it allows operators to increase quality-of-service levels. Let’s look at a situation in which there are two carriers over one physical wireless link and where the operator supports two types of applications, each with a different class of service: streaming video (high) and email (low). ABC can give priority to the streaming video service by placing its bytes more frequently onto both carriers than the e-mail service. If there is deterioration in one of the carriers, ABC immediately adjusts accordingly, still prioritizing the video bytes over the e-mail bytes. If there is improvement in the transmission rate of one of the carriers, ABC immediately adjusts to that situation. In all cases, the transmission of the higher class-of-service streaming video is prioritized over EL-mail. In all cases, the capacity of the entire wireless link is maximized even as the traffic is allocated by priority.
Multi-carrier ABC makes the most efficient use of the total capacity of a wireless link taking into account the operator’s quality of service goals. Operators who deploy ABC over wireless links enjoy a higher level of network resiliency. They maximize the use of precious network resources by maximizing capacity while providing the best available service to their users.
About the author
Eirik Nesse is VP Product Strategy at Ceragon. He is responsible for the global strategy for Ceragon’s microwave product portfolio and associated products. Formerly, he was the Chief Technical Architect at Nera Networks where he worked in various positions and has more than 27 years of industry experience. Mr. Nesse holds a BSc degree in Electronic Engineering from University of Stavanger. Mr Nesse resides in Bergen, Norway.