Telefonaktiebolaget Lm Ericsson (publ)

Jan Ingemar Swerup

Per-Olof Nerbrant

Bj&ouml;rn Jonsson

Krister T&ouml;rnqvist

Walter Ghisler

Bjorn E Jonsson

Bo Lindell

Johan Per Falk

Johan Kristofer Olsson

Bj&ouml;rn Erik Rutger Jonsson

Leif Magnus Nilsson

In a method and apparatus for assigning the values or functions to be represented by the keys of a keypad in a mobile communication device, the keys are capable of representing different values or functions based on the occurrence of a predetermined event. A detector is used to detect the occurrence of the event. Depending on whether the event is detected, the keys are assigned to represent a different set of values or functions.

Method and apparatus for keypad representation in a mobile communication device

A digital input symbol is transmitted to a receiver by determining one or more formant frequencies that correspond to the digital input symbol. In one embodiment, a pre-programmed addressable memory is used to map the set of possible digital input symbols onto a set of corresponding speech units, each comprising a superposition of one or more formant frequencies. A signal is then generated having the speech units. The signal is supplied for transmission over a voice channel. This may include supplying the signal to a voice coder prior to transmission. In another aspect of the invention, a forward error correction code (FEC) is determined for the digital input symbol, and the one or more speech units are modified as a function of the forward error correction code. In this way, the FEC may also be transmitted with the encoded input symbol. The modification may affect any of a number of attributes of the speech units, including a volume attribute and a pitch attribute.

Embedded data in a coded voice channel

Mapping of digital data symbols onto one or more formant frequencies for transmission over a coded voice channel

A system and method are disclosed in which a service provider in a first environment of a first plurality of competing, overlapping mobile networks has at least one service node. The service provider offers subscriptions based on SIM modules from at least one of a second plurality of mobile telephone operators in a second environment. The first plurality of operators has agreements for interconnect traffic with the second plurality of operators. Mobile users that are visitors in the first environment can communicate, through any appropriate network selected from the first plurality of mobile networks, which avoids the detouring of incoming calls to the visiting mobile users.

System and method for accessing mobile networks

A mobile radio network includes a number of mobile radio systems, each having a mobile radio services switching center which conveys calls between a number of cordless subscribers and a public switched telephone network which is common to the mobile radio systems which convey calls between a number of cordless subscribers, and a public switched telephone network which is common to the mobile radio systems which convey calls between wire-connected subscribers and also to the cordless subscribers via the mobile radio switching centers. If a cordless subscriber has roamed from its home system to a visitor system, a call from a third system can be transferred generally over the home system and the public network to the subscriber. A service node is assigned to each of the mobile radio systems and each such node keeps an account of where the home subscribers of respective mobile radio systems are located and, in cooperation with other service nodes, can connect a call from a subscriber in the third mobile radio system to the roaming subscriber without needing to load the remaining systems. The system also includes corresponding connection procedures, a subscriber telephone set and a method of registration in the network.

Registration and connection in a communication network

Growing community of inventors

Knivsta, Sweden

Jan Ingemar Swerup