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Point-to-Multipoint networks. Point-to-Multipoint networks. Applications for Point-to-Multipoint networks LMDS – Local Multipoint Distribution Systems MMDS – Multi-channel Multipoint Distribution Systems FWA – Fixed Wireless Access BWA – Broadband Wireless Access WLL – Wireless Local Loop
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Point-to-Multipoint networks WRAP 0973B
Point-to-Multipoint networks • Applications for Point-to-Multipoint networks • LMDS – Local Multipoint Distribution Systems • MMDS – Multi-channel Multipoint Distribution Systems • FWA – Fixed Wireless Access • BWA – Broadband Wireless Access • WLL – Wireless Local Loop • Characteristics of PtMP • Base stations (AUs, hubs) typically have wide-beam sector antennas • Base station antennas are directed to cover area of interest • Clients (CPEs, terminals) have narrow-beam antennas • Client antennas are directed towards the base • Means to plan for low interference • Frequency assignment • Polarisation assignment • Maximum range planning • Antenna directional discrimination WRAP 0973B
P-t-MP in WRAP • Definition of a specific Group: MP Station • Comprises one base station with a number of sector stations. To each of these a number of Clients is associated. • Sector antennas have a fixed azimuth and tilt • Thus not automatically directed towards the clients. • Client antennas are automatically directed in azimuth and tilt towards their sector station • Traffic: Station property Number of Channels • For clients: Defines the traffic requirement of the client • For sectors: Defines the total capacity of the sector station • Total traffic load on a sector station is calculated as the sum of the number of channels for each of its associated clients. WRAP 0973B
Types of networks • Networks are of one of the following types: • FDD/FDMAFrequency Division Duplex/Frequency Division Multiple Access • FDD/TDMAFrequency Division Duplex/Time Division Multiple Access • TDD/TDMATime Division Duplex/Time Division Multiple Access WRAP 0973B
Network type Interference in sector receivers Interference in client receivers Frequency assignment Comment FDD/FDMA Contributions from- All other sectors- All clients Contributions from- All other sectors- All clients Assigns one frequency to a sector and one frequency each to its associated clients. The sector transmits on one frequency and receives on a different frequency for each associated client. FDD/TDMA Contributions from- All other sectors- All clients outside own sector Contributions from- All other sectors- All clients outside own sector Assigns one frequency to a sector and one different frequency to its associated clients The sector transmits on one frequency and receives on another frequency, the same for all associated clients. TDD/TDMA Contributions from- All other sectors- All clients outside own sector Contributions from- All other sectors- All clients outside own sector Assigns one frequency, the same for the sector and its associated clients. The sector transmits and receives on the same frequency. Interference contributions WRAP 0973B
Interference contributions • Sectors are associated to a base station • Clients are associated to a sector • Note that a sector may be a client to another sector • Traffic load/remaining capacity is calculated. WRAP 0973B
Examples of map displays • Antenna lobe widths may be shown • - Left: Both sectors and clients • - Right: Sectors only WRAP 0973B
Supporting tools for P-t-MP • Frequency Assignment • Automatic and manual assignment of frequencies and polarisations • Interference • Calculations of interference between stations • Coverage • Calculations of sector coverage based on power budget • Finding the best spots for base stations (where a base covers all or the most of client locations) • Finding suitable spots for clients • Determination of required antenna heights • Link Performance • Calculations of power budget, outage, fading margins etc • Profile Viewer • Check for line-of-sight WRAP 0973B