Mobile radio network

• US 4,667,202 A
• Filed: 09/24/1984
• Issued: 05/19/1987
• Est. Priority Date: 09/28/1983
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Neyen, Hans-Juergen v. d., Haderer, Anton, Kammerlander, Karl
• Primary Examiner(s): Blum, Theodore M.
• Assistant Examiner(s): CAIN, DAVID C
• Application Number:
  US06/653,704
• Time in Patent Office: 967 Days
• Field of Search: 343/457, 343/394, 343/396, 455/33, 455/31, 455/53, 455/54, 455/56, 179/2 EB
• US Class Current: 342/457
• CPC Class Codes: H04B 7/2621 using frequency division multiple access [FDMA] H04B7/2615 takes precedence
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A mobile radio network comprises a plurality of base stations in a mutual three-dimensional arrangement in the manner of a cellular system. A respective, rigidly prescribed plurality of immediately adjacent, neighboring radio zones forms a radio zone group in which the frequency channels available are repeated. A problem area occurs in the design of radio zones in that the ground-bound radio propagation dependent on terrain and the nature of the built-up area leads to irregular field intensity distributions and radio zone boundaries; however, the radio zones must be designed according to the distributions of the radio traffic density. A solution for the traffic-qualified radio zone boundary is provided which is best suited for the detection of radio zone boundaries. The identificaiton of the radio zone boundary of two mutually-adjacent radio zones as a criterion for the transfer of mobile subscribers into a different radio zone is provided through a relative range measurement as a comparison of the distance of a mobile subscriber from two or more base sections and an evaluation of the phase difference of their signals is carried out. This transit time measurement is executed by way of the organization channels for operationally-ready radio subscriber devices and in the voice channels for radio subscriber devices involved in a call, the latter upon the use of the measurement receiver of the radio base stations.

Claims

1. A mobile radio network comprising:

a plurality of mobile subscriber stations;

a plurality of base stations in a mutual three-dimensional cellular system arrangement defining a plurality of radio zones of which immediately adjacent zones form a radio zone group in which each of the number of frequency channels is repeated, and in which at least the radio organization-oriented signaling is performed in digital form between the base stations and the mobile subscriber stations via duplex organization channels;

means for controlling transfer of mobile subscriber stations from one radio zone to another including means for performing a relative range measurement and comparing the distance of a mobile subscriber from at least two of said base stations and evaluating the phase differences of their signals for identifying the radio zone boundary of two neighboring radio zones as a criterion for transferring a mobile subscriber station to a different radio zone via the organization channel for an operationally-ready subscriber station and via the voice channel for a subscriber station engaged in a call;

means in each of said base stations for transmitting, in the organization channel, equi-reference phase signals with respect to all the base stations and information unique to the respective transmission radius corresponding to the respective traffic qualified radio zone boundary; and

means in each of said mobile subscriber stations for evaluating the transmission in response to the differences in transit time of the transmissions and the radii information so that the radio zone boundary is determined as a straight line centrally located between two base stations having identical transmission radii and a hyperbola with different transmission radii with the peak of the hyperbola being shifted towards one of the base stations with respect to the central line in accordance with half the difference between the radii.

2. A method of operating a mobile subscriber network of the type in which there is a plurality of mobile subscriber stations and a plurality of base stations in a mutual pre-dimensional cellular arrangement, in which a rigid-prescribed plurality of radio zones immediately adjacent one another forms a radio zone group in which the overall available frequency channels are repeated, in which at least the radio organization-oriented signaling is performed digitally between the base stations and the mobile subscriber stations via duplex organization channels, and in which each of the base stations comprises a measurement receiver having a control incorporated in the synchronous system of the base station, the method comprising the steps of:

transmitting equi-phase signals from the respective base stations;

performing a relative range measurement by receiving and comparing the distance represented by the signals from at least two base stations and comparing their phases to identify the radio zone boundary of two neighboring radio zones as a switching criteria by determining a first sum transit time of a signal between a first base station and a subscriber station and a second sum transit time between that subscriber station and a second base station with a radio location receiver and determining the distance between the first and second sum transit times as the relative range,

determining the first sum transit time including transmitting a signal from the first base station to the subscriber station and retransmitting the signal from the subscriber station to the first base station, measuring, in the first base station, the round-trip transit time and dividing the same in half to provide one-way time, transmitting a signal including the one-way time to the subscriber station, and retransmitting the signal including the one-way time from the subscriber station to the second base station.

3. In a mobile radio subscriber network of the type in which there is a plurality of mobile subscriber stations and a plurality of base stations in a mutual three-dimensional cellular arrangement, in which a rigidly-prescribed plurality of radio zones immediately adjacent one another forms a radio zone group in which the overall available frequency channels are repeated, in which at least the radio organization-oriented signaling is performed digitally between the base stations and the mobile subscriber stations via duplex organization channels, and in which each of the base stations comprises a measurement receiver having a controller incorporated into the synchronous system of the base stations in each of the base stations, in which each of the base stations comprises a central control unit for broadcast data control, the improvement comprising:

means for identifying the radio zone boundary of two neighboring broadcast zones as a criterion for switching mobile subscribers into another broadcast zone including means for making a relative range measurement by comparing the distance of a mobile subscriber from at least two base stations and evaluating the phase difference of their signals;

for operationally-radial subscriber stations means for measuring the difference of the transit time of the signals of identical reference phases emitted by said base stations in the time slots of the organization channel and means for evaluating the signals of identical reference phase containing information concerning the radii corresponding to the traffic-conditioned radial zone boundary and detecting the radio zone boundary as a straight line in the center between two base stations for mobile subscriber stations given identical radii signaling and, given different radii signaling, detecting the radio zone boundary as a hyperbola whose apex is shifted in accordance with half the radii difference towards one or the other side of the center with respect to identical radii; and

for mobile subscriber stations in operation, means for performing the relative range measurement in response to the radio signal transit time, comprising means for providing the sum of the transit time between the first base station and a subscriber station and between the subscriber station and a second, neighboring base station and means for identifying the range between the subscriber station and the second base station and between the subscriber station and the first base station in response to the difference of the sum transit time and the transit time of the signal between the subscriber station and the first base station.