Abstract A mobile telephony system includes an internal part-system (6), which is installed in a building (1) and an external part-system (7). The internal part-system has internal base stations (BSI) which are connected to a mobile switching centre (MSC), to which external base stations (BS1, BS2) are also connected. The mobile telephony system is assigned a frequency band which comprises a plurality of channels. The external part-system is divided into cells (C1, C2, C3) and has fixed channel assignment with a few channels to each external base stations (BS1, BS2). The internal part-system is adaptive and the internal base stations (BSI) have access to all channels of the system. In order to determine whether a mobile station (MSI) belongs to the internal or to the external part-system, an internal identification word is transmitted from the internal base stations and an external identification word is transmitted from the external base stations. When the signal strength of the internal identification word exceeds a threshold value, the moble station transmits an internal identification word to the internal base stations (BSI). If the signal strength falls beneath this treshold value, the mobile station (MSI) identifies itself to the external part-system (7).
A mobile telephony system intended for indoor and outdoor subscriber use, and comprising an external part-system for outdoor use which includes external base stations of relatively high signal strength and connected directly to a mobile switching centre, and an internal part-system for indoor use and having internal base stations of relatively low signal strength which are connected to the mobile switching centre, wherein - the two part-systems (6, 7) have traffic channels essentially for call transmissions and control channels essentially for assignment and change of the traffic channels; - at least one of the traffic channels of the internal part-system has the same frequency as the traffic channels of the external part-system; - the inner part-system (6) has adaptive channel assignement; - an internal identification word (IDI) which is unique to the internal part-system is transmitted from the internal base stations (BSI) on the control channels in the internal part-system (6); - an outer identification word (IDO) which is unique to the external part-system is transmitted from the external base stations (BS1, BS2) on the control channels in the external part-system (7); - a mobile station (MSI) detects a signal quality for the control channel of the internal part-system on which the internal identification word (IDI) is transmitted; - the mobile station (MSI) transmits an internal identification signal (IDIR) to the internal base stations (BSI) when the detected signal quality exceeds a desired quality measurement; and - wherein the mobile station (MSI) transmits an external identification signal (IDOR) to the external base stations (BS1, BS2) when the detected signal quality is beneath the desired quality measurement.
Claim 2
Dependent Claim
23 words
A mobile telephony system according to Claim 1, wherein the internal base stations (BSI) are connected directly to the mobile switching centre MSC.
Claim 3
Dependent Claim
29 words
A mobile telephony system according to Claim 1, wherein the internal base stations (BSI) are connected to the mobile switching centre (MSC) via a wire-bound telephone network (PX, 10).
Claim 4
Dependent Claim
29 words
A mobile telephony system according to Claim 1, wherein the signal quality detected is a measurement of the signal strength of the control channel of said internal part-system (6).
Claim 5
Dependent Claim
16 words
A mobile telephony system according to Claim 1, wherein the external part-system has fixed channel assignment.
Claim 6
Dependent Claim
26 words
A mobile telephony system according to Claim 1, wherein the internal base stations are connected to a mobile switching centre (MSC) via a subscriber exchange (AX).