When you switch on a mobile, it establishes a connection with the network via radio waves to the nearest mast. But, unfortunately for the majority of us who live in built up areas, it is far from easy for these signals to travel from mast to phone. They have to combat a combination of obstacles, including buildings, cars and even people, as well as the geographical barriers of the area.
The waves, as they're travelling, bounce off these objects, creating a very complicated pattern of waves that can not only block coverage, but create interference. It's like when you drop a stone into the centre of a pond. It creates a series of fairly uniform waves travelling out from the splash, but when these waves hit the sides of the pond, as when radio signals hit an object, they create a series of erratic new waves. These waves ripple in many directions and interfere with the waves coming out from the centre - just as radio waves bouncing off objects interfere with others.
However, now the era of a true wireless or cordless office is not far off with Bluetooth technology enabling devices like laptops, mobile phones and PCs to communicate via short range radio signals without wires or cords. But imagine the mess of signals that will be created by a large number of computers, phones and other devices sending radio signals to each other in an office or building.
Trinity College scientists have used mathematical models based on computational electromagnetics to predict how radio waves will act in different environments, such as hilly or mountainous areas, city centres with high buildings, or low-lying areas.
Using these models, which feed on data from computer generated 3-D maps, telecommunications engineers will be able to see how radio waves sent from a certain mast will act in a certain region. This information will help to decide both where to locate masts and how much power will be needed to get a clear signal to wireless users. Dr Peter Cullen, who is heading up the team at Trinity College, said different terrains and types of ground will affect the amount of energy available to a mobile unit.
Now the group are looking at how doors, windows and walls effect radio waves. They are also looking at how radio waves act in and between buildings. Interference in the form of echoes - like the ghosting when you turn on your TV and there is the shadow of another picture over the channel that is on - also affects wireless devices. The advanced planning tools for next generation systems are important because, with the amount of data, a number of different waves will be used to send information (voice, data and video) to a phone at high speeds.
Using a number of separate radio waves will not only allow more information to be sent, but will also allow The increased demand for the use of mobile networks for sending rich information means broadband radio signals will be used to give larger bandwidth. But Dr Cullen says that broadband is much more susceptible to interference than the current narrowband communication used by GSM networks.
Down the road, when Trinity's mathematical modelling becomes accurate and fast enough, it could mean that a piece of software in a phone could know the environment it is working in and then judge the best way to receive and send a signal.
The modelling could also be used in the actual operation as well as planning of a network, to maximise its capacity. Dr Cullen says the team will develop a new generation of rigorous, rich, accurate and robust software tools telling you how radio waves propagate in an indoor environment. He says current models . The Trinity team says they will provide tools that are trustworthy and accurate in every building and environment. So a company using their modelling software could see what strength of signal is available in different locations in the building and what interference is created.
As well as optimising the use of a network, the software will also be used to pinpoint the location of different mobile devices more accurately, they say.