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MVDS Solution |
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Since April 2003 we announced availability of equipment set for 100Mbps Full Duplex LMDS System. The equipment could be tailored according to customer's need. It is not a big secret for the telecom operators and their clients that all of already deployed or projected LMDS (MVDS) solutions have a principal shortcoming. That's a speed of upstream (return link) from a client station to provider's base station or an ISP. To put the question more precisely, we have to speak about speed-to-cost ratio of upstream link. When a client would like to get something faster than a simple dial-up or xDSL upstream link, the cost of return link skyrockets. So exactly the cost of return links is one of primary problem that prevent telecom operators from rapid widening of LMDS networks customer base.
In case of duplex, local access points will be used to provide upstream links
From marketing viewpoint, an LMDS duplex system will be in a greater demand from many SME/SOHO (Small and Medium Enterprises/Small Office - Home Office) clients if a telecom operator could provide relatively inexpensive return links which connection speeds are comparable with downstream link speed. While on a first look it seems that most of small clients don't have a need in broadband uplink - unless their business is directly involved to telecom market, that's vision trends to be outdated. We see more and more evidences of highly integrated small and medium businesses with extremely intensive data exchange. This tendency is actively popularized by leaded IT vendors, - for example, by Microsoft with their series of e-commerce products and integrated solutions. That means the increasing number of applications, which require high data exchange speeds. In the next turn we get the continued growth in high-speed wireless links. ELVA's Full Duplex LMDS equipment set based on an idea of local wireless access points for those LMDS subscribers who need high-speed return link. Since this idea is not a 'know how' by itself, it would be a winning one in case of availability of relatively inexpensive client-side transmitter to local access points. Then, local access points are connected to network operator backbone through fiber optics cable or other broadband communication media. The set of ELVA's LMDS equipment is intended to cover a cell of about 3.5km radius (for 30cm client dishes) and consist of the following devices:
For a duplex client station there are receiver and transmitter with separate dishes within the client equipment kit. It allows tailoring operation distance range either for receiver and transmitter as main base station and local access point station could be on various distances from customer site. That means the dishes of different size may be required to build a reliable downstream and upstream links. More over, shipping separate receiver and transmitter makes client equipment kit is cheaper in manufacturing than in case of a single client transceiver. While the main LMDS base station broadcasts in DVB-S standard with incapsulated IP packets, the client receiver in duplex version uses DVB-S in downstream link, but the upstream link transmitter emits the pure TCP/IP. The client upstream link transmitter is based on ELVA's PPC 40/42 family of 100Mbps wireless Ethernet links and therefore also has 100Mbps upstream link speed.
Fig.2 Base station with 2 client stations in ELVA's lab
In ELVA's Full Duplex LMDS equipment set an each local wireless access point has receiver base station, which receives upstream IP from client transmitters. The network management of client upstream links is implemented on TDMA principle. A client station receives a service signal from main base station allowing client transmitter to communicate with local access point station within allowed time slot. The network session length was selected in a way to support VoIP (Voice over IP) limitations for client upstream link. This guarantees an equal and high QoS (Quality of Service) for each client, connected to local wireless access point. Thus not IP data only but voice also could be transmitted on client upstream link. Our measurements show that up to 100 client transmitters could be connected to local access point and VoIP service would be available for all of them. The LMDS network management software including TDMA module and soft-based IP-incapsulator was written by ELVA's engineers. It runs on Linux-based server. During a series of tests it was confirmed that client stations can use cheap and widely available 100Mbit Ethernet LAN cards and ELVA's TDMA module for network communications. Linux-based PC controller is used as network router at a client side to provide IP connectivity for client PCs. These all give confidence to ELVA Company that high link speed and equipment compatibility are achieved under strict limitations on total cost of LMDS equipment either for network providers and their clients within SME/SOHO market niche. Additional information in PDF format:
Please send your requests on this product to sales@elva-1.spb.ru Specs
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