G.992.5 ADSL2+ Annex M

Standard Brief
ITU-T (ITU Telecommunication Standardization Sector) ADSL2/2+ Annex M specifies a new standard for ADSL service over POTS (Plain Old Telephone Service) by doubling upstream data rates. Through this new feature, service providers can create and offer value-added but bandwidth-consuming services, such as video conferencing, VoIP, VoD (Video on Demand), etc. Users do not have to suffer traffic congestion when enjoying these services as well as surfing the Internet. Moreover, with doubled upstream bandwidth, general users can be their own service providers by setting up media server center and delivering video programs for remote access.
Billion's Annex M products are fully compliant with the G992.3 ADSL2 and G.992.5 ADSL2+ Annex “M” standard. We offer the possibilities for service providers and users to expand their emagination in terms of creating diversified services and applications.

Technology
'Annex M' is an extension to the G.992.5 ITU-T International Telecommunications standard and enables the higher upstream speeds by increasing the upstream frequency range available. To double upstream bandwidth, Annex M shifts 138KHz from downstream frequency to upstream frequency. Therefore, upstream bandwidth can range from 25KHz to 276KHz.

Take BEC 7402G for example, we compared the test result of ADSL2+ Annex M and Annex A. We found that at 1Kft, Annex M's upstream data rate can reach 3000Kbps whilst Annex A can only reach 1100Kbps. And at 18Kft, Annex M's upstream data rate can reach 300Kbps and Annex A can reach 290Kbps. Though the difference is smaller, but Annex M is still higher than Annex A.

Note: The corresponding CO DSLAM is using Conexant chipset.
Under ideal conditions, the upstream rate can reach up to 3Mbps using ADSL2+ Annex M.

Benefits & Applications

High-speed upstream data rate: By increasing the upstream data rate to approximately 2.5 Mbps (up to 3Mbps under ideal conditions), users can experience faster and smoother data transmission than ever. Users do not have to suffer traffic congestion when sending and receiving important data or video stream.

Cost-Saving: To address business user's need for fast and cost-effective network services, Annex M provides an alternative to T1 or G.SHDSL which delivers similar upstream bandwidth but cost a lot more.

Enable diversified multimedia services: With the increase of upstream data rate, business users can setup Web server or FTP server at corporate to provide remote access for files sharing and some bandwidth -consuming applications, e.g. VoIP, video Conference. Moreover, general users, mobile workers or travelers can setup media server center at home broadcasting video programs to the Internet, then they can watch the high-quality shows remotely through the laptop or PDA devices.

Setup Multimedia Center for Remote Access

Note: Real data rate of Annex M products may depend on different DSLAMs and network environment.