Inner Mongolia Mobile has deployed a cost-saving solution to allow significantly increased GSM connectivity in remote villages without increasing costs...
Inner Mongolia Mobile, which is a subsidiary of China Mobile Communications Corporation, is believed to operate the world's largest unified, contiguous all-digital mobile network as well as the world's largest mobile subscriber base. The new solution is based on technology supplied by RAD Corporation.
To accommodate its rapidly growing customer base, Inner Mongolia Mobile needed to double the capacity of the existing BTS (Base Transceiver Stations) it currently maintains in each village. The challenge was that the company would need an additional E1 line to connect to the new base station. Not only would this extra link be more expensive, but multiple E1 lines might not always be available at every cell site.
Given that E1 lines from the BTS are typically under-utilised, however, Inner Mongolia Mobile opted for a solution from RAD that combines E1 multiplexing and GSM optimisation, enabling the transport of two optimised E1 circuits over a single E1 link.
RAD's solution is the Vmux-400, an Abis optimisation gateway that eliminates redundant silence and idle frames in the Abis protocol in the BTS-to-BSC (Base Station Controller) cellular backhaul links. Depending on the periods of call silence and the signalling, Vmux-400 can achieve an optimisation ratio of up to 3:1 without any increase in operating costs (Opex) by multiplexing the backhaul traffic into a single E1 uplink for transport to the BSC.
"For cellular operators that rely heavily on TDM leased lines from terrestrial carriers, this means that the number of links needed for Abis backhaul can be drastically reduced, with a corresponding reduction in Opex," notes Thomas Q Lu, President of RAD China. "The Vmux-400 also provides a valuable head start for mobile operators in their migration to 3G, since optimisation enables operators to free up leased lines used for 2G/2.5G traffic and apply them to their 3G networks," Mr Lu explains. "In this way, they can avoid the time delay and costs associated with installing additional leased lines," he adds. The RAD solution was proposed and provided to Inner Mongolia Mobile by Ubridge, an authorised RAD distributor in the People's Republic of China.