Vmux-400 A-bis and A-ter Optimization Gateway Achieves Better Bandwidth Utilization and Reduces Bandwidth Expenses

The Vmux-400 GSM A-bis and A-ter optimization gateway from RAD Data Communications enables cellular operators to achieve better bandwidth utilization and reduce backhaul expenses.

This is particularly important in remote or rural areas lacking an extensive terrestrial telecom infrastructure, where many cellular operators backhaul traffic over satellite links. In built-up areas where landlines exist but are not currently available, microwave radio links might be employed for quick connectivity. The Vmux-400 is particularly beneficial in these applications, maximizing the amount of traffic that can be supported over the limited available bandwidth of these links. Moreover, due to the high cost of satellite and microwave transmission, the Vmux-400’s return on investment is very fast.

The Vmux-400 maximizes bandwidth utilization by eliminating redundant silence and idle frames in the A-bis protocol. Using the Vmux-400, optimization ratios of up to 3:1 can be achieved. When used in conjunction with other Vmux voice compression and bandwidth optimization components, cellular operators can significantly reduce both their operational expenditure (OPEX) and capital expenditure (CAPEX). The Vmux-400 is particularly useful in applications where landlines do not exist or are not available and expensive satellite and/or microwave links, with their limited bandwidth, are used to backhaul the traffic.

Voice compression technologies enable mobile operators to slash bandwidth on the BSC-to-MSC segment of the backhaul network, as well as between MSCs and the MSC-to-PSTN section. Because voice traffic between the BTS and the BSC is already compressed, no further compression is recommended. By applying technology that optimizes the A-bis protocol interface (the encapsulated traffic running between the BTS and the BSC), however, it is possible to realize significant reduction in bandwidth resulting in cost savings.

The Vmux-400 is a standalone device, complementing RAD’s Vmux voice compression products, which enables cellular operators to lower backhaul costs across their Radio Access Network. The Vmux-400 optimizes the A-bis (BTS-to-BSC) bandwidth utilization, while the A (BSC-to-MSC) interface and the E (MSC-to-MSC /PSTN) interface are further optimized for greater bandwidth efficiency by RAD’s Vmux-2100 voice trunking gateway. Used in tandem, the Vmux family of compressed voice and bandwidth optimization devices reduce Opex while enabling cellular operators to expand their network infrastructure and introduce new services, without additional costs.

The Vmux-400 supports optimized data, GPRS and EDGE over multiple timeslots for cellular transmission networks, as well as standard GSM A-ter optimization and AMR codec rates from 4.75 to 12.2 kbps. The standards-based Vmux-400 is interoperable with equipment from major switch vendors, such as Alcatel, Ericsson, Siemens, Huawei, Nokia, and Motorola, facilitating connectivity in a multi-vendor environment.

A unique feature allows for reliable regeneration of the TDM-based clock for synchronized network operation. This enables the use of packet-switched networks for the transport of cellular voice traffic.

The Vmux-400 GSM A-bis and A-ter optimization gateway is a compact 1U high, half 19" wide unit that can be mounted in a 19" rack. The small form factor makes the Vmux an ideal solution for installation in small BTS cabinets. It can groom the traffic of two E1s over a single E1, serial or 10/100 BaseT Ethernet uplink.