Leadership in GSM Cellular Radio Access Networks (RANs)
STM’s GSM cellular base stations combine standard, high-performance processors with advanced software radio technology to deliver low-cost, power efficient radio access networks to serve rural areas and other special applications (e.g., maritime, military, and emergency services). Both BTS and BSC functions can operate easily on the same equipment local to each BTS site. All four common GSM bands are supported (850, 900, 1800 and 1900 MHz), easily allowing for multi-band configurations in a modular fashion. Using the Internet Protocol (IP) on all backhaul interfaces in an optimized manner with intelligent soft-switch control, the Superpico system supports local call routing and direct communication between remote sites over any IP network (satellite and/or terrestrial). This greatly reduces backhaul network costs and eliminates the need for specialized GSM interface “compressor” units and the expensive circuit switched technologies traditionally used in GSM networks.
STM’s RAN solutions support GPRS, EDGE and the standard GSM vocoders (FR, EFR and AMR). They are compliant with the 3GPP GSM & GPRS ETSI Release 99 standards.
Low Cost, Environmentally Friendly SuperPicoTM System
STM’s SuperPico system is the most power-efficient base station technology for serving low-density rural populations and other remote applications that require excellent coverage range. The system is composed of two types of compact, light-weight modules: the SuperPico BSS Controller and the SuperPico Cellular Radio . Each controller supports up to three Cellular Radios and each Cellular Radio supports 1 TRX. This results in a small, scalable eco-friendly base station that is easy to deploy and runs on just a few solar panels. In a 3 TRX configuration, it consumes about 30 Watts per TRX (vs. more than 300 Watts per TRX for traditional GSM base stations). For a 1 TRX configuration, it consumes less than 33 Watts (vs. a traditional base station which consumes about 500 Watts at a minimum).
As base stations typically consume 80% of the electricity in a cellular network, the SuperPico system will not only lower costs, it will also have less of an environmental impact, while still providing the range required to cover rural town centers plus surrounding rural areas up to 15 km in diameter, with the ability to penetrate thick building walls within the town.
Complete solar power systems cost in excess of $10,000 (fully installed) for each 100 Watts required by the base station, assuming 24 x 7 operation with a limited number of hours of “peak sun” output on the worst days of the year. While diesel generators offer lower CAPEX per Watt they impose significant OPEX in terms of fuel, fuel delivery and fuel security costs. Thus, no matter which power sources are used, mobile operators save considerable CAPEX and OPEX using the SuperPico system in areas where the electricity grid is either non-existent or prone to outages.
Rugged All-Outdoor Hardware for Fast and Easy Installations
Using its 20 years of experience in rural telephony, STM designed the hardware for the SuperPico base station system with knowledge of what is required to install and operate reliable telephony services in harsh environments. The rugged, compact SuperPico base station modules are mounted entirely outdoors (e.g., on a roof, tower or pole). No shelter or indoor space is required. No air-conditioning or fans are required. Each SuperPico module is sealed for protection against wind-driven rains, sand, salt and dust with an IP66 rating. Each module has a powder coated aluminum enclosure and stainless steel mounting brackets resist corrosion. An entire SuperPico base station (including RF power amplifiers, BTS electronics and BCS) consists of only a few light-weight modules (3 to 5 kilograms each) which connect with a few cables. This enables easy, fool-proof installation by one or two locally trained technicians who may be unfamiliar with the complexities of traditional base station installations.
Advanced Software Radio Technology
STM has partnered with Vanu Inc., the leading cellular mobile software radio technology provider. This partnership has resulted in many efficiency and performance benefits for the SuperPico system. Industry standard computing platforms yielding the highest performance per Watt are used for processing the GSM waveforms and protocols using advanced software, enabling both BTS and BSC functions to run in the SuperPico BSS Controller module. The BSS Controller unit is connected to the SuperPico Cellular Radios –which are typically mounted on the tower near the antennas – via Gigabit Ethernet. This assures minimal signal losses up the tower. The Cellular Radio performs the following functions: low-noise amplification and digital filtering for Rx, power amplification and digital filtering for Tx, and duplexing and other low-level digital signal processing using flexible FPGA technologies. This allows for remote software and firmware updates to the entire SuperPico base station. The Cellular Radio module also includes a crystal oscillator to maintain frequency stability of 0.05 ppm over 10 years, and excelling timing stability for long range operation.
Local Call Routing and Single Hop Village-to-Village Calling
The presence of a local BSC at each BTS site improves call hand-over performance and also enables both local call routing and single hop village-to-village calling over an IP satellite network. Unlike traditional base stations which must send all traffic back to the Mobile Switching Center (MSC), voice and data traffic can flow via the most efficient route available over an IP backhaul network which is using modern soft-switch technology for GSM calls. As part of a total Radio Access Network solution, STM provides the required soft-switch and media gateways that interface via standard SS7 protocols to the PSTN and existing MSC equipment.
Maximum Backhaul Efficiency and Convenience
Backhauling traffic to an MSC typically represents the largest component of OPEX for BTS sites serving remote and rural areas, since satellite links must often be used. The SuperPico system makes using satellite links very cost-effective and easy. An STM SatLink technology can be used in the BSS Controller as an Integrated Backhaul Element, sharing the same power source and coupling internally to the rest of the base station for maximum reliability and simplicity. Furthermore, bandwidth consumption is greatly reduced through a combination of IP stack protocol optimizations implemented in both the SuperPico and SatLink products. Support for local call routing and single hop connections between villages also reduces bandwidth consumption significantly. Microwave and other terrestrial backhaul options can also be used where available instead of satellite, or they can be used with satellite links providing a more reliable backhaul network.
BTS Scalability
SuperPico BTS sites can be built efficiently with just one TRX (for small villages) or up to 6 TRX for larger towns using multiple BSS Controllers. The use of AMR Half-Rate codecs then doubles the capacity, enabling SuperPico to scale up and handle sites with more than 80 Erlangs of traffic. Since capacity is added in a module fashion, there is never the requirement make a large equipment investment.
|
|
