Microwave Technology :
What is WiMAX Technology :
- In telecommunications, information can be transmitted between two locations using a signal that can be either analog or digital in nature. In analog transmission, the signal carrying the information is continuous, for example when talking into the telephone a voice is transmitted as a voltage signal of continuously varying amplitude (power) and frequency. With digital transmission, the signal is a series of discrete levels, or pulses, with a ‘1’ and ‘0’ corresponding to “on” and “off,” respectively. Analog transmission systems have been almost completely replaced since the 1970’s in telecommunications by digital systems. Now even analog traffic, such as voice calls, are converted to digital signals (a process referred to as ‘sampling’), to facilitate long distance transmission and switching.
- Microwave radio is totally transparent to the information carried across the link, which can be voice, data, video, or a combination of all three. Transport can be in a variety of formats, including more traditional circuit-switched Time Division Multiplexing (TDM), or more recent packet-based data protocols such as ATM, Frame Relay or IP, often carried using the ubiquitous Ethernet. In some cases, packetized data can be overlaid on a TDM frame structure such as PDH, SDH or SONET.
Microwave radio offers a number of compelling advantages over cable/fiber-based transmission:
- Rapid Deployment – a microwave link can be installed in as little as one day
- No right-of-way issues – radio spans all obstacles such as roads, railways, etc., avoiding any requirement to seek permissions that inevitably are costly and introduce time delays
- Flexibility – the capacity of a microwave link can be easily increased at minimal or even no cost
- Easily crosses city terrain – In many metropolitan and city authorities, street digging to install fiber is either extremely restricted, prohibitively expensive or is even banned outright
- Radio infrastructure already exists for many networks in the form of rooftops, cellular masts and existing radio transmission towers
- Microwave radio is not susceptible to common catastrophic failure of cable systems caused by cable cuts, and can be repaired in minutes instead of hours or days
- Better resilience to natural disasters (flood, earthquakes)
A modern microwave radio system consists of three basic components forming a radio terminal, with two terminals required to establish a microwave communications link, commonly referred to as a “hop”. A digital modem interface with digital terminal equipment, converting customer traffic to a modulated radio signal. A radio frequency (RF) unit for up-converting the modulated carrier signal to microwave or millimeter-wave frequencies and amplifying the signal up to around 1 watt (referred to as 0 decibels, or dB in RF terminology); and a passive parabolic antenna to transmit and receive the signal.
Two very important characteristic of digital microwave radio transmission is its immunity to noise, and the ability of the radio to operate in the presence of adverse environmental conditions.
Modern microwave systems can be designed for extremely high link availabilities in excess of 99.999%, translating to link downtimes of literally seconds annually, which is easily comparable to that provided by supposed “error-free” optical fiber systems.
The Blue Zone™ adopted native-IP Microwave links which utilizes more advanced, more reliable technology than legacy TDM Microwave.