Abstract: An arrangement for determining radio coverage provided by a telecommunications system to a user of a mobile device is disclosed. In the case of a GSM or UMTS mobile device, if the device is in the idle mode (step A) and if a paging operation is not scheduled (step B), the mobile device records and stores on the mobile device a characteristic of the radio coverage provided when the mobile device is at each of a plurality of locations visited by the user of the mobile device (step C). The arrangement also enables retrieval of the recorded and stored characteristic so that radio coverage provided to the device for the user at the locations can be evaluated. If the telecommunications system includes a plurality of networks, the mobile device will record and store the characteristic for each of the plurality of networks. The arrangement then enables the radio coverage provided by the respective networks to be evaluated, and an informed choice as to the best network for that particular user can be made.

Abstract: An arrangement for determining radio coverage provided by a telecommunications system to a user of a mobile device is disclosed. In the case of a GSM or UMTS mobile device, if the device is in the idle mode (step A) and if a paging operation is not scheduled (step B), the mobile device records and stores on the mobile device a characteristic of the radio coverage provided when the mobile device is at each of a plurality of locations visited by the user of the mobile device (step C). The arrangement also enables retrieval of the recorded and stored characteristic so that radio coverage provided to the device for the user at the locations can be evaluated. If the telecommunications system includes a plurality of networks, the mobile device will record and store the characteristic for each of the plurality of networks. The arrangement then enables the radio coverage provided by the respective networks to be evaluated, and an informed choice as to the best network for that particular user can be made.

Abstract: A method and apparatus for combining video signals with key signals whilst maintaining the integrity of the video signal and minimizing the effect of alias components. An analyser detects whether there are any high frequency components which would otherwise cause alias components. If such high frequency components are present, then low-pass filtering occurs. If such high frequency components are not present, then no unnecessary filtering occurs so as to maintain the absolute integrity of the video signal.