Wireless Broadband

Wireless Broadband
The type of wireless broadband most often used by businesses to link facilities at different addresses is a local multipoint distribution system (LMDS). It has a total bandwidth of 1.3GHz, which is achieved by sending data short distances in the microwave frequencies of the 27.5GHz-to-31.3GHz radio spectrum.

Network: The LAN sends data to a point-to-multipoint router located with an antenna on the roof. Antenna signals are picked up by one of several other antennas about three miles apart that receive and broadcast signals to other antennas.
Cell Links: The cells are linked by point-to-point antennas, which broadcast a highly targeted signal between two antennas that are aimed at each other.
Identification: Although all LANs in the LMDS network receive the same radio transmissions, each pays attention only to the signals that bear its address.
Internet: A request made for an Internet page is passed from one cell to another until it reaches a cell that functions as a distribution node. That cell passes the request to a land-wired Internet connection.

Fixed Wireless Network Architecture
To offer high-speed Internet services, a fixed wireless carrier creates a data network that operates over MDS, MMDS, or ITFS frequencies. The following diagram provides a high-level look at a typical broadband fixed wireless network, including a fixed wireless headend that connects to a central antenna that broadcasts data directly to home and business locations, or to smaller cell sites, which in turn reach remote pockets of businesses or residences. Data is either sent back upstream from customers over wireless frequencies or through traditional dial-up telephone modem connections.

Fixed Wireless Headend
The fixed wireless headend is the control point for the broadband access network. A carrier-class IP switch or router interfaces with the backbone data network offering connectivity to remote content servers, as well as the global Internet. This switch/router also connects to a wireless cable modem termination system (CMTS) that coverts data from a wide area network (WAN) protocol, such as packet over SONET, into digital signals that are modulated for transmission over the wireless network. These signals are then converted into wireless microwave frequencies through a transceiver and broadcast through an antenna to customer home or business locations. Like their counterparts that operate over cable TV systems, a wireless CMTS unit typically provides a dedicated 27 Mbps per downstream 6 MHz data channel that is shared by active users. Upstream speeds are typically below 1 Mbps. Content and application servers are typically located at the fixed wireless headend, as are network management and operations support systems. If the carrier were offering IP telephony, voice calls would be directed by the headend router to a IP telephony gateway, and then onto the public switched telephone network (PSTN).
Business Environment
In a business environment, an antenna and transceiver receive the incoming data signal and transmit it over coaxial cable lines to the broadband modem, which interfaces with a local area network (LAN) through an Ethernet hub, switch or router, providing access to multiple users. See other:
Home Environment
An antenna and transceiver at the home receive the incoming data signal and transmit it over in-home coaxial cable lines to a broadband modem. The modem connects to an Ethernet card in the PC with Category 5 cabling and RJ-45 connectors or a Universal Serial Bus (USB) interface.