Establishing a communication link

DETAILED DESCRIPTION This objective is achieved by a method and devices having the features of the independent claims.
The dependent claims define preferred embodiments of the present invention.
The invention is based on the idea to execute, before a call indication is received from the telecommunications network, a preliminary step in which at least one property of the short range radio channel is negotiated.
The mobile station then enters a power saving mode.
When the actual call indication arrives, the mobile station is activated and linked to the telecommunications network using the at least one negotiated channel property.
The invention provides several advantages.
Since the mobile station enters the power saving mode after the preliminary step discussed above, low average power consumption and long battery life is achieved.
Furthermore, the preliminary negotiation step may be rather time consuming, especially if it includes a further step of identifying available mobile stations.
Since this step, according to the invention, is performed before the actual call indication arrives, the response time from arrival of the call indication to establishment of the communication link is shortened considerably.
This is very convenient in the case of telephone (voice) connections and may be indispensable for the exchange of data packets.
Furthermore, there is enough time for the preliminary negotiation step to find an optimal set of channel parameters.
This may include time consuming operations, for example determining an optimal transmission power level depending on the level of noise signals in the environment.
In the terminology used here, a "property of the radio channel" may be any property or setting that affects the communication process via the channel.
This includes properties of the transceivers of the local and mobile stations as well as properties of the method used in controlling said transceivers.
The term "negotiating" includes all kinds of communication processes, for example any request/response process having one or more steps as well as any issuing of one or more commands for setting one or more channel properties concurrently or sequentially