The customer, initially a division of Info-Quest, is the first private Greek operator, which provides a fixed and mobile telephony as well as Internet services.
Directing its commercial activities on the large urban centers, the operator has developed a second-generation mobile telephony network by means of base stations and a broadband fixed wireless access network, point-to-multipoint, which operates at 3.5 GHz. Simultaneously, it has developed a national network with leased lines and privately owned transmission systems.
The customer holds a 3.5 GHz Fixed Wireless License in the Greek market (FWA). The license consists of 2x21 MHz sub-bands (3476.5 – 3497.5 MHz and 3576.5 – 3597.5 MHz), which fits the current development plans of WiMAX technology deployment. AT the same time, the network already had an installed base of digital TDM switches.
WiMAX Network Requirements
The Greek operator launched a WiMAX broadband access network from Alcatel-Lucent in order to outspread its fixed telephony capacity and reach, primarily to residential customers and the market of small to medium businesses.
The customer required a WiMAX network to provide:
• Infrastructure for high-speed broadband
• Readiness for triple-play offering
• Voice services to rural areas, so that to fill in the gaps
Initially the customer deployed a small-scale pilot WiMAX network with 100 friendly users. The pilot field trials were designed to assess the ability of the WiMAX equipment to provide unfailing and reliable services with QoS guarantees, through a user-friendly and efficient provisioning platform.
Following the successful pilot, the customer launched a WiMAX network in a discreet area for live customers in Q1 2007.
The Challenge: Fixed Voice over WiMAX
The customer's fixed telephony services are based on PSTN technology with Class-5 AXE-10 Ericsson TDM switches (LE). The service includes domestic and international calls with advanced telephony services, such as call waiting, 3-way calls, call forwarding, caller ID, free number, legal interception (LI), CLASS 5 and Intelligent Network (IN) features.
The customer wanted to use WiMAX to fill in the gaps in the network and to provide, thus, voice and data service for the rural places, while preserving the existing TDM based PSTN network. Regulation required voice services that are not based solely on softphones (Skype, etc.) or voice over broadband (VoB).
To provide voice services that utilizing WiMAX , the customer had two options:
• Implementing a new VoIP Softswitch
•Reusing its current infrastructure
Implementation of a Softswitch and the VoIP peripherals (For example, trunk gateways to connect the VoIP network to the PSTN) would have required a high up-front capital expenditure, as well as additional operating expenditures. Therefore, the simple and cost-effective solution was the employment of an access gateway.
The Commatch 6004 SIP to V5.2 Access gateway provided immediate uptime, and complete interoperability with the existing infrastructure
With this solution at hand, the TDM switch (Local Exchange) provides the call processing, billing and administrative functions, while the Commatch 6004 provides the signaling translation and media conversion towards the SIP endpoints.
Click here for more information on Commatch 6004.