Microwave applications. G3 and G4 microwave backhaul
Problem Description
Mobile operators are trying to follow increasing demands for faster packet transmission. However, the residual G2 part of the network still has to run simultaneously. Consequently, in most cases both TDM and packed microwave transmission are necessary. Often, there are nodes to which optical fibers just cannot reach.
Proposed Solution
Combining microwave and optical transmission techniques offers effective and efficient solutions. Due to the ability of packet transmission to adopt the transmission speed, adaptive modulation ACM is becoming an important characteristic of microwave point to point links. The TDM share of traffic gets much higher availability, because it uses lower modulation schemes (QAM4-16 for example). In good weather conditions higher modulation schemes are taking place. Bit rates at about 400 Mbit/s full
duplex are normal for higher modulation techniques, combined with wide band radio channels of 56 MHz. Basic Design Network designers are always doing their best to protect the traffic in a network. Therefore ring topology is very common. Combining adaptive modulation, ring topology, layer 2 and/or 3 protection and fiber on some sites, very effective solutions are made available.
In case of heavy rain, causing transmission bit rate to decrease, routers are able to reroute the packet traffic.