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TechnologyThe key to every deployment is choosing the right technology that meets the need. With this in mind Zhone supports a wide variety of physical layer access technologies as well as higher layer features to ensure that the services of choice can be easily and cost effectively deployed. Solving the Issues of Access DeploymentsRPR TransportResilient Packet Ring (RPR) defined by the IEEE 802.17 standard is a protocol designed to carry packet traffic over rings. RPR was defined to provide capabilities such as resiliency and scalability to Ethernet transport. RPR uses a dual, counter-rotating, fiber ring topology (similar to SONET/SDH and FDDI), with an outer ring and inner, sometimes called ringlets. The use of both fiber rings ensures resiliency as well as makes use of 100% of the capacity of the fiber.
MTM - Multimedia Traffic ManagementMTM™ (Multimedia Traffic Management) is a suite of powerful application and service management features, enabling Carriers and PTTs to support new revenue-generating services on their broadband access network. By enabling voice, video, data, online gaming, and other services in all areas of the network, service providers can offer new bundled services that will increase the income potential from each broadband access line. EFM and Loop BondingEFM, or Ethernet in the First Mile, refers to any Ethernet-based access technology defined by the IEEE under the 802.3 specification (specifically, 802.3ah). In addition, using multiple bonded copper pairs to deliver high-speed ethernet services is also used outside of 802.3, typically to deliver bonded Ethernet over DS1 or DS3 circuits. While technically, the term "EFM" refers to 802.3 compliant technology only, the term is often used loosely within the industry to refer to any Ethernet Access technology, often focusing on Ethernet over Copper.
Pseudowire Emulation - PWE3Pseudowire Edge to Edge Emulation (PWE3) is a protocol designed to emulate "wires" or end-to-end circuits over a packet network. These emulated wires, because they constitute a virtual circuit, are ideal for carrying circuit-based technologies such as TDM voice and/or data services. Unlike older circuit emulation technologies, PWE3 is able to run an adaptive, synchronous clock across the packet network, allowing TDM devices to interconnect as if there were a physical "wire" between them. The packet network can be copper or fiber based. Routing and Bridging VideoThe MALC works within the IP standards adopted for IPTV, IGMP may be used in either a bridged or routed mode for multicast of video streams at the access end. In bridged mode, the MALC performs a Layer 2 snooping function, allowing Router in the core network to perform the Layer 3 IGMP multicast control and set up/tear down of channels. In a Routed mode the MALC has its own IGMP proxy function built-in. Therefore, multicast control and channel changing occurs at the node, and is distributed across the network. Both methods are supported fully in standards and both perform the same functions - the difference being where in the network the intelligence and control exists. Emergency Standalone (ESA)The MALC is equipped with the Emergency Standalone (ESA) feature that allows it to provide features when communication to the Class 5 or Softswitch is interrupted. If the uplink to the network is broken, the MALC continues to provide basic call routing and calling features. The Zhone’s MALC support two topologies for ESA. The first is RT-MALC to a Media Gateway via Softswitch using SIP (ESA if link to Softswitch/Media Gateway is broken) and the second is RT-MALCs to COT MALC with VG using SIP PLAR (ESA if link to COT MALC is broken or GR303/V5.2 link goes down) ReachDSLReachDSL is a DSL technology originally developed by Paradyne Corporation (acquired by Zhone Technologies 2005) to solve many of the issues with mass-deployment that exist today. ReachDSL technology was specifically designed to enhance standard ADSL deployments by allowing service providers to expand their broadband market to 100% of their customers that are currently offered POTS. In addition ReachDSL solutions allow service providers to take this one step further and reduce cost by utlizing a technology and products that solve their provisioning issues and reduce their operational costs by working with the ADSL network model that they have been deploying for years.
SHDSL, 2Base-TL and Spectral CompatibilityNoise within a binder is a real concern for deploying any service over voice-grade copper, which is susceptible to cross-talk and noise. SHDSL was developed to be a quiet technology, being more spectrally friendly than T1/AMI, HDSL2 and HDSL4, especially in symmetric applications. G.991.2-2003 often called SHDSL.bis, the foundation for the transport of 2Base-TL EFM, offers more throughput still, with less noise. This is accomplished by increasing the efficiency of a given frequency (more throughput with less noise), while also increasing the available frequency range (more throughput, with additional noise). The balance provides a flexible technology that can operate well within the limitations of T1.417, as well as providing higher data rates up to 5.696Mbps. While higher data rates do impose more noise, EtherXtend's cross-talk cancellation features can limit the impact of this noise within a bonded group. That is, when four or eight pairs are bonded together, the lines within a group are balanced to limit noise generation, and also to limit the impact of noise within the group, in order to maximize performance.
T1 and Other InterferersAll technologies -- including T1, HDSL2/4, ADSL2+, VDSL2, and SHDSL -- share common frequencies, and therefore interfere with each other. Noise from one service impacts another, reducing the maximum throughput of all services within a binder. SHDSL, especially using EFM (2Base-TL), helps because it is spectrally friendly. The only way to truly reduce interference is to remove interferers completely, but this isn’t always possible. Zhone’s EtherXtend helps by offering several alternatives, including the support for a variety of T1/E1 signaling options on T1/E1 EtherXtend devices, and also by offering T1/E1 emulation over SHDSL.
Loop Testing with SELT & DELTThe integration of loop test capability into ADSL2+ IP DSLAMs and BLCs, as well as ADSL2+ CPEs, is one of the many ways in which Zhone is helping to lower the operational costs of our customers -- the same basic underlying goal of all Zhone products and services: to provide the products, tools and services needed to lower the Operational Expenses (OPEX) of carriers, service providers, and PTTs.
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