Research in Motion (RIM), Apple Inc., and 13 other phone makers and wireless service providers are being sued for patent infringement by patent holding company over 3G and 4G technologies that figure in determining when devices can switch cells in a mobile network.
The patents in question includes a process for determining the manner in which handover is performed in a mobile radio network including plurality of cells, where each cell is associated with a base station supporting communication with a mobile device, the court document said.
The patent process, according to court documents, includes steps for monitoring the quality of a signal as a function of time transmitted between candidate base stations and the mobile phone.
A handover refers to the transfer of user connection from one access point to another.
“In mobile telephone, it is necessary to maintain established user connection even if the user is changing locations, or the radio access environment surrounding the user is changing, while the connections is still active,” said Steelhead in its filing.