Cellular radio on Inspec

Just 40 years ago, in April 1973, Motorola demonstrated the first widely acknowledged public demonstration of a call using a hand-held cell phone. Although the first analogue networks (known as 1G networks) were introduced in various countries in the late 1970s and 1980s, it took until the early 1990s for mobile radios to be widely used across the world by the general public.

This coincided with the introduction of the first digital networks (2G networks) and a considerable reduction in the size of the handsets. The 3G networks with which we are familiar today were introduced in the early years of the 21st Century and it was at this stage that the data speeds and network coverage increased to such a point that use of the internet on these mobiles took off.

Now, as we pass the 40th anniversary of that Motorola demonstration, we are seeing the introduction of 4G networks with another leap in data communication speeds. For the first time with these 4G networks, voice calls are treated in the same way as data. You will often hear terms such as WiMAX and LTE (Long Term Evolution) associated with 4G networks.

A mobile phone is actually a sophisticated radio. It converts your voice into an electrical signal, which is then transmitted as radio waves and converted back into sound by the receiving phone. To be portable, mobile phones need relatively compact antennas and use a small amount of power. This means mobile phones can only send a signal over only a very short range. To connect over large distances they make use of a cellular network of phone masts. These huge phone masts pick up the weak signal from the phone and relay it onwards to other phone masts in order to get to the destination of the call. The phone also switches masts if you should move around whilst calling.

The first mobile phone applications began with voice calls; further developments saw the introduction of texts and picture messaging and this evolved on to audio-visual applications and data communications. We now have smartphones which act as MP3 players, cameras, video cameras, and internet terminals for communications and running applications (‘apps’), all in one small device. Mobile radio devices don’t have to be small though; new product categories have been introduced over the last few years where the sizes of some devices are starting to increase again after years of shrinking handsets; in particular, tablet computers, which really began with the iPad.

So what of the future? Coverage will improve and data speeds will increase. Mobile phone technology is still working its way into our lives and this will certainly continue, and many new applications will be discovered.

At Inspec, we have many Controlled Terms which are relevant to the field of mobile radio; some of the more important ones are listed below:

• 3G mobile communication
• 4G mobile communication
• antenna arrays
• broadband networks
• cellular radio
• cloud computing
• code division multiple access
• cognitive radio
• cooperative communication
• cryptography
• diversity reception
• electronic messaging
• femtocellular radio
• frequency division multiple access
• indoor radio
• Internet
• IP networks
• Long Term Evolution
• military communication
• MIMO communication
• mobile ad hoc networks
• mobile antennas
• mobile computing
• mobile handsets
• mobile radio
• mobility management (mobile radio)
• multimedia communication
• next generation networks
• OFDM modulation
• protocols
• radio spectrum management
• radiofrequency interference
• radio wave propagation
• railway communication
• smartphones
• social networking (online)
• telecommunication congestion control
• telecommunication network reliability
• telecommunication network routing
• telecommunication network topology
• telecommunication security
• telecommunication traffic
• video streaming
• WiMax
• wireless channels
• wireless LAN

The relevant Classification Codes are: