DLS 5500 In Stock

The DLS 5500 by Spirent is a specialized xDSL custom noise generator designed to facilitate the application of standardized or custom-generated noise shapes to a test circuit. This noise generator is specifically engineered for physical testing of various xDSL network access equipment, including ANSI, ETSI, ITU-T, DSL Forum, HomePNA, and EFM devices, boasting a bandwidth of 30 MHz. The DLS 5500 system comprises a rack-mountable PC chassis, a keyboard, a mouse, a custom Arbitrary Waveform Generator module, control software, and a sample noise library.

The DLS 5500 is designed with various convenient features, including four noise output ports located on the back panel. By combining PC architecture, a custom Arbitrary Waveform Generator (AWG) module, and specialized control software, the DLS 5500 effectively generates and synthesizes noise with exceptional precision. This integration of hardware and software enables the generation of realistic noise replicas for the testing of xDSL network access equipment. Users have the capability to generate noise that closely mimics the spectral pollution induced in a wire pair of an actual network access cable. The noise generator's software implements two distinct noise sources: crosstalk and RFI ingress.

The DLS 5500 calculates a noise sample based on the user's selected noise profiles, which is then downloaded into the noise generator for direct output without any additional signal processing. The DLS 5500 is compatible with various noise injectors, each with its own distinct electrical characteristics such as injector loss, frequency response, and bandwidth. This noise generator possesses the capability to accept user-generated time-domain files for reproduction. The system operates by repeatedly playing back a series of data samples at a specified rate, utilizing RAM memory housed within the noise generator. The user is responsible for loading the data samples into memory and generating the desired noise type accordingly.

The DLS 5500 employs a noise profile, which represents a Power Spectral Density (PSD) description of the crosstalk noise observed at the receiver of the xDSL modem being tested (near the point of injection). Initially, the noise generator reads a file containing a noise profile that specifies the type of noise to be generated. Subsequently, it synthesizes and generates the noise PSD, applying it to the wireline or simulated wireline near the receiver of the xDSL modem under test via a noise injection mechanism. If necessary, the DLS 5500 can generate noise at a higher level to compensate for the insertion loss caused by the noise injection network. Under normal circumstances, the noise generator is used in conjunction with an external injector circuit that conditions the signal, ensuring it is balanced and provides a high-impedance or current output.