System and method for channel allocation in a radio telephone system for an underground railway
First Claim
1. A radio telephone system comprising:
- at least a first base station A having two antennas for communicating with a mobile radio in areas α and
β
respectively and a second base station B having two antennas for communicating with a mobile radio in areas γ and
δ
respectively, wherein a first set of channels is allocated to the first base station A, the first set of channels including a channel Cα
for serving area α and
a channel Cβ
for serving area β and
a second set of channels is allocated to the second base station B, the second set of channels including a channel Cγ
for serving an area γ and
a channel Cδ
for serving area δ
, areas β and
δ
being in radio interference over an interference zone, characterised in that channel Cδ
is additionally allocated to the first base station A to serve area α and
the first base station A has first discriminating means which are operative to detect a call on channel Cδ
in area α and
to prevent the channel thus occupied from being directed to the antenna serving area β
, and wherein channel Cβ
is additionally allocated to the second base station to serve area γ and
the second base station has second discriminating means which are operative to detect a call on channel Cβ
in area γ and
prevent the channel thus occupied from being directed to the antenna serving area δ
.
1 Assignment
0 Petitions
Accused Products
Abstract
A radio telephone system is installed in an underground railway system. The telephone system has base stations A, B at respective railway stations 1, 2 and the base stations serve leaky cables serving the railway stations and further cables extending along the tunnel bores interconnecting the railway stations. To improve the availability of channels available as station calls to users of mobile radios within the areas of the railway stations, switches 20 are incorporated to prevent any channel occupied as a station call being directed into the cable serving the tunnel. This enables channels allocated as train call channels at one base station to be re-used as station call channels at an adjacent base station.
17 Citations
9 Claims
-
1. A radio telephone system comprising:
- at least a first base station A having two antennas for communicating with a mobile radio in areas α and
β
respectively and a second base station B having two antennas for communicating with a mobile radio in areas γ and
δ
respectively, wherein a first set of channels is allocated to the first base station A, the first set of channels including a channel Cα
for serving area α and
a channel Cβ
for serving area β and
a second set of channels is allocated to the second base station B, the second set of channels including a channel Cγ
for serving an area γ and
a channel Cδ
for serving area δ
, areas β and
δ
being in radio interference over an interference zone, characterised in that channel Cδ
is additionally allocated to the first base station A to serve area α and
the first base station A has first discriminating means which are operative to detect a call on channel Cδ
in area α and
to prevent the channel thus occupied from being directed to the antenna serving area β
, and wherein channel Cβ
is additionally allocated to the second base station to serve area γ and
the second base station has second discriminating means which are operative to detect a call on channel Cβ
in area γ and
prevent the channel thus occupied from being directed to the antenna serving area δ
. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- at least a first base station A having two antennas for communicating with a mobile radio in areas α and
-
9. A method of allocating channels in a radio telephone system comprising:
- at least a first base station A having two antennas for communicating with a mobile radio in areas α and
β
respectively and a second base station B having two antennas for communicating with a mobile radio in areas γ and
δ
respectively, wherein a first set of channels is allocated to the first base station A, the first set of channels including a channel Cα
for serving area α and
a channel Cβ
for serving area β and
a second set of channels is allocated to the second base station B, the second set of channels including a channel Cγ
for serving an area γ and
a channel Cδ
for serving area δ
, areas α and
γ
being in radio isolation, areas α and
β
being in radio interference, areas γ and
δ
being in radio interference and areas β and
δ
being in radio interference over an interference zone, characterised in that channel Cδ
is additionally allocated to the first base station A to serve area α and
the first base station A detects when a call is made on channel Cδ
in area α and
prevents the channel thus occupied from being directed to the antenna serving area β and
wherein channel Cβ
, is additionally allocated to the second base station to serve area γ and
the second base station detects when a call is made on channel Cβ
in area γ and
prevents the channel thus occupied from being directed to the antenna serving area δ
.
- at least a first base station A having two antennas for communicating with a mobile radio in areas α and
Specification