BEIJING -- Inner Mongolia Mobile, a subsidiary of China Mobile Communications Corporation, which maintains the world's largest unified, contiguous all-digital mobile network and the world's largest mobile subscriber base, has deployed a cost-saving solution from RAD Data Communications that will allow it to significantly increase GSM connectivity in remote villages without increasing costs.

To accommodate its rapidly growing customer base, Inner Mongolia Mobile needed to double the capacity of the existing BTS (base transceiver station) it currently maintains in each village. The challenge was that they 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 underutilized, however, Inner Mongolia Mobile opted for a solution from RAD Data Communications that combines E1 multiplexing and GSM optimization, enabling the transport of two optimized E1 circuits over a single E1 link.

Vmux-400 Achieves Optimization Ratio of up to 3:1 This RAD solution is the Vmux-400, an Abis optimization 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 signaling, the Vmux-400 can achieve an optimization 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 optimization enables operators to free up leased lines used for 2G/2.5G traffic and apply them to their 3G networks," Lu explains. "In this way, they can avoid the time delay and costs associated with installing additional leased lines," he adds.

China Mobile Communications Corp.