Method for realizing contention resolution in mobile communication system

background the invention

Field of the Invention

The present invention relates to a random access (random Access) in a mobile communication system and in particular a A method for generating mobile IDs (IDs mobile) in a mobile Communication system and the use of a mobile station for such a Process.

discussion of the prior art

Usually, is not a competitive situation, the collision of "physical Parameters "as For example, an access time window (access slot), a preamble signature (Preamble signature) and a spreading code (spreading code) but the collision of mobile IDs of mobile stations. In a mobile communication system, mobile stations according to the physical Parameters distinguished from each other. For example occurs in a competitive situation, which is a synchronization of mobile IDs of different mobile Stations when the mobile stations access the same time window use. A conventional A method for realizing the resolution of the competition in a mobile communication system will be described below with reference to the annexed Drawing explained. <figref idrefs="S13">1</figref> shows a flow diagram, the conventional A method for realizing the resolution of the competition shows in the mobile communication system.

With in reference to <figref idrefs="S13">1</figref> sends an first mobile station a Direktzugriffsssignal (random access signal) to a base station with a first arbitrary mobile ID through a common channel to request more services. A second mobile Station sends a Direktzugriffsssignal to the base station with the first random Mobile ID, which for said first mobile station has been used, over a random access channel, of a predetermined time difference from the random access of the first having mobile station. The first and second random mobile ID the first and second mobile station may conflict or not when the physical parameters of the preamble signature and the access time slots are identical or different from each other are.

Then leads the Base station, the following operation according to the random access requests the first and second mobile station through. When the first random mobile IDs the random access signals from the first and second mobile station collide with each other, so that the base station to receive a signal can, through the base station transmits no signal at the first and second mobile station. Then repeat the mobile stations the random access after the lapse of a predetermined time of its inner timer. When the base station a signal according to the random access the first random mobile ID but received by the first mobile station has no random mobile ID received from the second mobile station has, it transmits an access grant signal ACK for the first any mobile ID, which indicates that it optional to Access has received from the first mobile station. Accordingly reserved channels the first and second mobile stations according to the access grant signal ACK of the first random associated with the mobile ID, which are transmitted from the base station, which results in the creation of a competitive situation.

Especially, because the second mobile station, the access grant signal ACK from the base station dependent from the first random Mobile ID receives, which was generated by a random access request by themselves, although the random access of the first random mobile ID not by the Base station has been received, detects the second mobile station mistakenly that its random access is successful. Thus, the reserved Channel in the grant signal ACK of the first random Mobile ID is assigned to the second mobile station. Accordingly transferred the first and second mobile station signals including their directory numbers, the their identities meet, through the reserved channels, which are assigned to them.

Then the base station scans the directory numbers in the signals are included on the The reserved channels have been received from the first and second mobile stations, duplicating a signal that the directory number of the first mobile contains station to the first mobile station with the mobile ID, which in the optional had access success and then sends it. The first mobile station compares the signal that contains its directory number has been sent by the base station, with the signal transmitted through them , and leads a continuous communication through, because the two signals are identical to each other. The second mobile station compares the ACK with their directory number transmitted from the base station has been, with the signal that it has itself delivered. Then try the second mobile station stops the random access or re it after the lapse of a predetermined time of its inner Timer because the two signals are different from each other. Thereby, the dissolution the competition between the first and second mobile Station realized.

The Base station operates the dissolution the competition between the first and two&lt;?page 3?&gt;th mobile Station by the previously described method, when the signal through the random access of the first random mobile ID from the second mobile Station receives, but not the signal in accordance with the optional Access to the first random Mobile receives -ID of the first mobile station.

furthermore is a method for random access in a mobile communication system a plurality of mobile stations and at least one base station that this operated mobile stations, includes, in <patcit><text>US 5517681</text></patcit> disclosed.

Around to avoid the collision problem, which is caused when mobile stations the same random identifier in their Requests for a use either free access, the base station sends a call message to the mobile stations in a first time window to mobile Stations should be entitled, to send a message to the random access to the base station. The respective mobile station transmits a message for a random access, that contains a particular random identifier, the z. B. a random number, similar as in the example of <figref idrefs="S13">1</figref>. to the base station in a second time window, the first on the Time window follows. Then the base station sends a response message, contains a random number, and further containing the identifier of the second time window whose Identifier, the serial number of the second time window, which is calculated from the time slot following the page message.

The WO-A-9849857 also describes a method for an random access in a mobile telecommunications system. The The method used for. Example, a S-ALOHA scheme for random access, at the mobile station generates a data packet for random access and sends to the base station. The data packet includes an application area and a data area. The lead-in area includes a Signature code spread with a first spreading code, said first spreading code associated with a predetermined sector is. Furthermore contains the rich Datenbe the data packet for random access certain information for random access including mobile (user) identity information in the form of different random numbers (similar to the example of <figref idrefs="S13">1</figref>) To message collisions to avoid.

Around However, the dissolution the competition to realize the need conventional methods for providing a random access in a mobile communication system needlessly electric power of the mobile and / or base stations and deteriorate the efficiency the communication system.

Thus there is a continuing need for an alternative way, a provide random access in a mobile communication system, the one or more of the problems due to limitations and disadvantages of the prior art avoids.

abridged version the invention

According to the present Invention, a method for generating mobile IDs in a mobile Communication system is provided in which a plurality of mobile stations respectively generate different mobile IDs to a random access provide a base station, comprising the steps of: the mobile stations generating different mobile IDs using of at least two physical parameters, one of which is a Introduction different signature contains; send the mobile stations a random access signal using the generated mobile IDs to the Base station; and the mobile stations receive access grant signals from the base station.

According to a further aspect of the present invention is a use of a mobile station in such a method for generating a Mobile ID provided in a mobile communication system.

According to a embodiment the present invention, each mobile ID a preamble signature region, an access time slot area and a random number range.

According to a another embodiment in accordance with the preamble signature region, access time pane and the random number range 4 bit, 3-bit or 9 bit.

According to a another embodiment contains the mobile ID is one of several access time windows.

According to a another embodiment the base station uses the mobile ID of the random access signal and then transfers an access grant signal to the mobile station, wherein the mobile-ID in the access grant signal is included.

According to a another embodiment the invention build multiple mobile stations different mobile identities from physical parameters of different preamble signature areas and Access time window areas on to try random access and thereby prevent an unnecessary Power, performance degradation the system and interference due to the resolution of the conflict.

&lt;?page 4?&gt;

It is self-evident, that both the foregoing general description and the following detailed Description are exemplary and explanatory only, and it is intended, further explanation of the invention in the claims provide.

Summary the accompanying drawings

The appended Drawings, which for a better understanding annexed to the invention and incorporated in this description and part of this specification represent, illustrate embodiments of the Invention and together with the description, the principles the invention to explain:

It show:

<figref idrefs="S13">1</figref> a flow diagram a conventional A method for realizing the resolution of a competition situation shows in a mobile communication system;

<figref idrefs="S13">2</figref> an example of a format a Mobile Identity (ID) for a proceeding a random access in a mobile communication system according to the present Invention is used; Fig and

<figref idrefs="S14">3</figref> shows a flow diagram, a method for a random access in a mobile communication system according to the present Invention.

Detailed Description of Preferred embodiments

following will now detail to the preferred embodiment of the present invention reference is made, examples of which in the accompanying Drawings are shown.

<figref idrefs="S13">2</figref> shows an example of Format a mobile ID or mobile identity (ID), which in a process for the random access in a mobile communication system according to the present Invention is used. Regarding<figref idrefs="S13">2</figref> is the mobile identity of a Introduction signature in a 4-bit preamble signature region, a Access time windows in a 3-bit access time window area and a random number in a random number range. <figref idrefs="S14">3</figref> shows a flow diagram, the method comprising for the random access in a mobile communication system according to the present Invention. Next, the method for random is Access in a mobile communication system according to the present Invention with reference to the accompanying drawings.

in the Case that the first and second mobile station a random try to access a base station, they have to cellular IDs, which are different from each other to access optionally, a competition to avoid. In particular, the control devices generate the transmitting device (RRC) of the first and second random numbers in the physical mobile station Parameters in the preamble signature region where access time pane and in the random number range to assign different mobile IDs, and then try using the generated mobile IDs randomly access. The preamble signature region, access time window area and the random number area corresponding to 4-bit, 3-bit or 9 bit.

The Mobile ID is divided into several regions and each bit of the areas is determined by the physical parameters. The number of the bits can vary and the mobile ID of each mobile station can be varied, if changes of the physical parameters. Z. B. generates the RRC of the first mobile station random numbers the physical parameters in the "0110" -Einleitungssignaturbereich and the "110" -Zugriffszeitfensterbereich the random number range, to a first mobile ID assign (ID1), and then sends a random access signal the base station. The RRC of the second mobile station generates accidentally Numbers corresponding to the physical parameters of the "1110" -Einleitungssignaturbereichs and "010" -Zugriffszeitfensterbereichs and the random number range to assign a second mobile ID (ID2) and then sends a random access signal to the base station.

Then the base station scans a reception state of the random access signals, received from the first and second mobile station, a Mobile ID to detect each received random access signal, and then sends access grant signals ACK to the mobile station with the mobile ID. D. h., When only the Random access signal to the first mobile ID (ID1), the first of the mobile station has been sent, is received, the base station transmits the access grant signals Contains ACK to the first mobile station that the first mobile ID (ID1). Accordingly searches the first mobile station access grant signals ACK, of the base station are sent to the access grant signal ACK to receive its first mobile ID, and then leads a communication through a reserved channel through is assigned to the base station and in the access grant signal ACK is included. The second mobile station retries a random access with the help of another mobile ID or stops after a predetermined time of its internal timer has elapsed, because they no access grant signal ACK respect its second mobile ID received from the base station.

&lt;?page 5?&gt;

in the Case that the base station only the random access signal from the receiving second mobile station, it transmits the access grant signals ACK to the second mobile station that the second mobile ID (ID2) contain. Accordingly searches the second mobile station, the access grant signals ACK, of the base station are sent to the access grant signal ACK of its second mobile ID to receive, and then performs communication by through a reserved channel by the base station assigned and included in the access grant signal ACK is. The first mobile station tries again, an optional Access by means of another mobile ID or stops it after a predetermined Time their internal timer has elapsed, because there is no access grant signal ACK has received from its first mobile ID from the base station.

According to the method to implement the resolution the competitive situation in a mobile communication system the present invention provide several mobile stations different mobile identities using physical parameters of different preamble signature fields and access time window areas, a random access to try an unnecessary Power consumption, the degradation in performance the system and interference due to the dissolution of the competitive situation is prevented.

It is for a professional course, that various Modifications and variations in the method for random access in a mobile communication system of the present invention can be made, without departing from the scope of the invention. Thus, it is intended, that the present invention modifications and variations of this Invention covers if they are within the scope of the appended claims.