Electronics patent of the month: Calculating total of mobile terminals in a cell
GB Patent Number: 2481721
Granted to: Vodafone Group
In recent months I have attended seminars where the same theme has come up time and again – namely, the exponential growth of data transmission in telecoms networks, and in particular, its effect on mobile networks. The recent launch by EE of the first 4G service in the UK is welcome and with the auction for the 4G spectrum now underway, we will soon be looking forward to improved mobile bandwidth performance.
This brought me to wonder, how are the (potential) 4G mobile operators placed to exploit their intellectual property for the benefit of their 4G customers? So in my search for this month’s Patent of the Month I came across GB patent no. 2481721, granted on 2 January 2013, to Vodafone Group plc.
This UK patent addresses head-on the challenges of maintaining high data rates in congested mobile cells without any degradation of service.
In a mobile telecommunications network, the state of communication between the network and its mobile terminals can either be active or inactive/idle. In the active state, as a mobile terminal moves from one cell to another, a communication session is maintained by performing a “handover” operation. In contrast, in the inactive/idle state, as a mobile terminal moves between different cells of the network, it performs “cell reselection” to identify the most appropriate cell on which to “camp” in order that the mobile terminal can be paged as appropriate.
One factor required to allocate network resources efficiently between different users in a single cell is the number of mobile terminals. In order to know the number of terminals in a cell, the location of each must be known.
However, when a mobile terminal is in its idle state, it may be difficult or impossible to determine its location. This means that, when a user moves his mobile from an idle state to an active state to use a specific data service, this will result in an unexpected drain on the cell’s resources. This could adversely affect all data users in that cell.
In order to address this problem, Vodafone has developed a method of accurately calculating the number of mobile terminals in a cell by collecting information relating to their location within the cell. Under the protected method, the cell controller instructs mobile terminals in an idle communication state to switch to an active state in order to obtain information about the location of the other mobile terminals.
This can be done by sending a dummy paging message to the terminal or by modifying the cell identification parameters.
Once the location information is collected, the cell controller may use it to determine the density of mobile terminals at a particular location. Resources can then be reallocated more efficiently.
This makes me think – come next summer, when 4G will be rolled out nationwide – does this innovation mean that Vodafone will provide a more reliable data service?
Michael Jaeger is a patent attorney at leading UK patent and trade mark attorneys, Withers & Rogers LLP.
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