BROADBAND ACCESS EVOLUTION NETWORK TECHNOLOGY TEST FOR THE EFFICIENCY OF LISTENING QUALITY USING VoDSL Sarhan M. Musa Department of Engineering Technology Prairie view A & M University, Prairie View, TX 77446 USA Abstract This paper presents a baseline test for the listening quality (LQ) using voice over digital subscriber line (VoDSL) access technology by using voice/listening quality(V/LQ) transmission with voice compression while countinously downloading file. The design of an experimental VoDSL network architecture is presented. We identify the efficiency of the LQ based on the following digital subscriber line (DSL) service levels, 640K/640K, 1.5M/384K, and 3.0M/512K for each American National Standards Institute (ANSI) loops. Key Words Voice over Digital Subscriber Line (VoDSL); Digital Subscriber Line (DSL); Integrated Access Devices (IAD); Listening Quality (LQ). 1. Introduction The next generations of telecommunications providers around the globe are engaging in the rapid development of a new service that will combine both data communications and telephony. VoDSL has been developed with the rapid increase of the Internet and of the data traffic through network convergence of voice and data [1]. VoDSL service has the capability to provide the customers with converged voice and data, including local and long distance telephone service, plus high speed Internet access, on a single DSL copper line. The tests and the requirements demonstrated of VoDSL equipment for voice functionality and voice quality (VQ) in the DSL forum technical report are in [2]. We used on our test asymmetric digital subscriber lines (ADSL), because it provides a “life-line” capability, so that if the power fails, one telephone line will still work. It has a lower bandwidth upstream than downstream. It transmits high bit rate data in the down direction from the central office (CO) to the subscriber (downstream), with typical bit rates from 1.5 to 8 Mb/s, and lower bit rate data in the reverse (up) direction from the subscriber to the CO (upstream), with bit rates from 64 to 640 Kb/s [3]. ADSL is used for asymmetric services to residential and small office home office (SOHO) customers. This paper contains results that can be used in evaluating VoDSL solutions that offers multiple voice connections simultaneously with data onto the high speed digital line offered by ADSL line. The results are based on the V/LQ of VoDSL. In Section 2, we present description of the network architecture for V/LQ test setup. In section 3, we have a discussion on the subscriber loop plant noise. Section 4 is the result of the tests performed while Section 5 is the conclusion. 2. Description of the network architecture We used the V/LQ transmission with voice compression while continuously downloading file to verify the ability to support up to eight derived lines and the LQ on the Integrated Access Devices (IADs) for VoDSL. The following DSL service levels were used 640K/640K, 1.5M/384K and 3.0M/512K for each ANSI loops. Figure 1 shows the fixed wireline networks test setup for the access evolution of broadband services using VoDSL technology for V/LQ transmission. We verified the V/LQ transmission with voice compression and the maximum number of line connections in compressed mode operation that can be supported without any problems based on figure 1. The Customers can have multiple IADs based on their needs. Each IAD has 4-8 telephone interfaces plus an Ethernet interface. We test one IAD based on VoDSL solutions. Eight telephones are connected to the IAD that resides in the customer premises through Plain old telephone service (POTS). Data from the personal computer (PC) source running file transfer protocol (FTP) is provided to the IAD via the Ethernet. IAD interconnects the customer’s premises Equipment (CPE) and ADSL service and it converts POTS to Asynchronous transfer mode adaptation layer type 2 (AAL2). It uses the same virtual path identifier/virtual channel identifier (VPI/VCI) for voice and data. So these have to be mapped to unique values before transmission on the same pipe out of the digital subscriber line access multiplexer (DSLAM), for example, 0/39 to 0/209. All the Voice calls are digitized in the form of AAL2 cells and sent over the 433-122 472