CN1965605B - Improved intersystem cell reselection from GERAN to UTRAN - Google Patents

Abstract

This invention describes a method for a cell reselection by a mobile station from a serving GERAN cell supported by a GSM/EDGE (global system for mobile communications/enhanced data rates for GSM evolution) radio access network (GERAN) to a UTRAN cell supported by a universal terrestrial radio access network (UTRAN). According to a first embodiment of the invention, the intended intersystem reselection behavior is reached without signaling changes. This can be a preferred mode for early implementations because signaling changes always take a longer time to reach the products on the field (both mobile and network updates are normally required). According to a second embodiment of the invention, the flexibility of signaling changes is used for an advantage.

Description

Improved intersystem cell reselection from GERAN to UTRAN

Cross References to Related Applications

This application claims priority to US Provisional Patent Application Serial No. 60/578,639, filed June 10, 2004, and US Application Serial No. 11/129,673, filed May 13, 2005.

technical field

The present invention relates to inter-system reselection optimization in mobile communication systems, and more particularly relates to cell reselection from GERAN to UTRAN.

Background technique

Existing cell reselection from 2G to 3G is based on the Universal Terrestrial Radio Access Network (UTRAN) Common Pilot Channel (CPICH) Ec/No (the energy received from the CPICH per PN chip and at the antenna connector of the mobile station Received overall power spectral density ratio) thresholds and based on the received signal code power (RSCP) level of the UTRAN CPICH relative to the received signal level (RXLEV) of the GSM/EDGE radio access network (GERAN) serving cell. In addition, if the applicable criteria S (Srxlev > 0 and Squal > 0) for the UTRAN target cell are not satisfied, cell reselection to UTRAN may be prohibited (reselection may still be triggered).

TeliaSonera proposed a new threshold based signaling change for the UTRAN CPICH RSCP improvement to control cell reselection from GERAN to UTRAN in addition to existing parameters. (For existing parameters see (1) Change Request 45.008CR205, Tdoc GP-040586, (2) Tdoc GP-040585, 19th GPP TSG-GERAN meeting, Concan, Mexico, April 19-23, 2004 "Background for WCDMA uplink best characterized by CPICH RSCP and downlink by CPICHEC/No", and (3) proposal "Need to study for Cell Re-selection specification changes" by Ari-Pekka Salovaara on October 6, 2004, 10 ,06,04).

There is currently no minimum receivable UTRAN CPICH RSCP threshold signaled in the Global System for Mobile Communications (GSM) when reselecting a UTRAN cell from GERAN. The consequence is that it is not possible to apply active reselection behavior when the mobile station will reselect an available UTRAN cell, whether or not the UTRAN cell is suitable (with practical hysteresis added to avoid ping-pong effects).

More specifically, if the reselection is only controlled with the existing Ec/No threshold (by setting the RSCP to RXLEV offset criterion to "minus infinity", i.e., allowing reselection regardless of the received signal strength indicator (RSSI ) than the target cell RSCP), the mobile device can reselect an unloaded UTRAN cell from far away from an uplink failure (especially if the UTRAN cell is at the edge of the UTRAN coverage). On the other hand, when this Ec/No threshold is set high enough (to guarantee uplink access), the mobile station may not be able to access the loaded UTRAN cell at all or at least the mobile station needs to should be closer to the target UTRAN site.

The origin of this problem, as explained in the TeliaSonera document referred to above, is that UTRAN CPICH Ec/No varies greatly depending on the loading of UTRAN cells and especially for cells at the edge of UTRAN coverage. This makes it impossible to set up a reselection that takes place at a point where the uplink is guaranteed to be operable, while at the same time causing the mobile station to reselect the UTRAN cell as long as both the uplink and downlink are operable (essentially Both UTRAN CPICH RSCP and Ec/No have sufficient levels). A minimum threshold based on CPICH RSCP is included in the applicable standard for UTRAN.

Contents of the invention

The object of the present invention is to provide a mobile station from a serving GERAN cell supported by a Global System for Mobile Communications/GSM Evolution Enhanced Data Rates (GSM/EDGE) Radio Access Network (GERAN) to a General Terrestrial Radio Access Network (GERAN) A method for cell reselection of UTRAN cells supported by UTRAN).

According to the first embodiment of the present invention, the inter-system reselection behavior involved is realized without signaling changes. This may be the preferred mode for early implementations as signaling changes often take longer to implement in products in the field (often both mobile device and network updates are required). According to a second embodiment of the invention, the flexibility of signaling changes is used as an advantage, so such changes are intended to be supported without being mandatory by mobile and network equipment.

According to a first aspect of the present invention, a method of cell reselection by a mobile station from a serving cell supported by a first radio access technology to a cell supported by a second radio access technology comprises the steps of: selecting a previous cell supported by a second radio access technology and reading and storing an RSCP applicable threshold from the previous cell; selecting, by the mobile station, a serving cell; and establishing, by the mobile station, a method for reselecting from the serving cell A reselection criterion for a cell, wherein the reselection criterion comprises at least one threshold comprising the RSCP applicable threshold plus an offset defined by the mobile station using predetermined criteria.

Further according to the first aspect of the present invention, the serving cell may be a serving GERAN cell, the cell may be a UTRAN cell, the previous cell may be a previous UTRAN cell, and the first radio access technology may be a GSM/EDGE radio access network (GERAN), the second radio access technology may be Universal Terrestrial Radio Access Network (UTRAN) and the RSCP applicable threshold may be the UTRAN RSCP applicable threshold. Additionally, the method may comprise the steps of determining whether reselection criteria are suitable for a UTRAN cell and, if so, reselecting the UTRAN cell by the mobile station. Furthermore, before the step of selecting a serving GERAN cell, the method may still include the following steps: selecting a previous UTRAN cell and reading and storing the UTRAN RSCP applicable threshold from the previous UTRAN cell. Still further, the offset may include a hysteresis value or may be defined using the mobile station's power capabilities.

According to a second aspect of the present invention, a computer program product comprises a computer readable storage structure embodied as computer program code thereon for execution by a computer processor having computer program code, characterized in that it comprises a Instructions for executing the steps of the first aspect of the invention are indicated to be executed by any component of the mobile station, GSM/EDGE Radio Access Network (GERAN) or Universal Terrestrial Radio Access Network (UTRAN).

According to a third aspect of the present invention, a method for cell reselection by a mobile station from a serving cell supported by a first radio access technology to a cell supported by a second radio access technology comprises the steps of: the mobile station selects a serving cell; and establishes, by the mobile station, first and second reselection criteria for reselecting a cell from the serving cell, wherein the first reselection criterion includes a threshold value comprising from The ratio (Ec/No) of the energy received on the Common Pilot Channel (CPICH) to the total power spectral density received at the antenna connector of the mobile station plus an offset added to this ratio by the mobile station, and the second weight The selection criteria include an RSCP threshold, the serving cell provides the mobile station with an offset from said ratio and the RSCP threshold.

Further according to the third aspect of the present invention, the serving cell may be a serving GERAN cell, the cell may be a UTRAN cell, the first radio access technology may be GSM/EDGE radio access network (GERAN), the second radio access technology may be Universal Terrestrial Radio Access Network (UTRAN) and the RSCP threshold may be a UTRAN RSCP threshold. In addition, the method may further comprise the steps of determining whether the first and second reselection criteria are suitable for the UTRAN cell and, if so, reselecting the UTRAN cell by the mobile station. Still a step further, the UTRAN RSCP threshold may include a hysteresis value or may be defined using the power capability of the mobile station.

According to a fourth aspect of the present invention, a computer program product comprises a computer readable storage structure embodied as computer program code thereon for execution by a computer processor having computer program code, characterized in that it comprises a Instructions for executing the steps of the third aspect of the invention, the instructions being indicated to be executed by any component of the mobile station, GSM/EDGE Radio Access Network (GERAN) or Universal Terrestrial Radio Access Network (UTRAN).

According to a fifth aspect of the present invention, a mobile station capable of performing cell reselection from a serving cell supported by a first radio access technology to a cell supported by a second radio access technology includes: receiving/transmitting/ a processing module, responsive to a threshold signal indicating an RSCP applicable threshold from the previous cell supported by the second radio access technology, for providing a received threshold signal indicating the RSCP applicable threshold; and cell reselection block, responsive to the received threshold signal indicating the RSCP applicable threshold, for establishing reselection criteria for reselecting a cell from the serving cell, wherein the reselection criteria include at least one threshold including the RSCP applicable threshold Add the offset defined by the cell reselection block using predetermined criteria.

Further according to the fifth aspect of the present invention, the serving cell may be a serving GERAN cell, the cell may be a UTRAN cell, the previous cell may be a previous UTRAN cell, and the first radio access technology may be a GSM/EDGE radio access network (GERAN), the second radio access technology may be Universal Terrestrial Radio Access Network (UTRAN) and the RSCP applicable threshold may be UTRAN RSCP applicable threshold. Additionally, the cell reselection block may determine whether reselection criteria are suitable for a UTRAN cell and, if so, reselect the UTRAN cell by the mobile station. Still further, the offset may include a hysteresis value or may be defined using the mobile station's power capabilities. Still further, the mobile station may include: a memory for storing the UTRAN RSCP applicable threshold.

According to a sixth aspect of the present invention, a mobile station capable of performing cell reselection from a serving cell supported by a first radio access technology to a cell supported by a second radio access technology includes: receiving/transmitting/ a processing module, responsive to a signal from the serving cell indicating the RSCP applicable threshold and the energy received from the Common Pilot Channel (CPICH) per PN chip and the total power spectral density received at the mobile station antenna connector The offset of the ratio (Ec/No) for providing the received signal indicating the RSCP threshold and the offset of the ratio; and the cell reselection block, in response to indicating the UTRAN RSCP applicable threshold and the ratio The offset received signal is used to establish first and second reselection criteria for reselecting a cell from the serving cell, wherein the first reselection criterion includes a threshold comprising the ratio (Ec /No) plus an offset appended to the ratio, and the second reselection criterion includes the RSCP threshold.

Further according to the sixth aspect of the present invention, the serving cell may be a serving GERAN cell, the cell may be a UTRAN cell, the first radio access technology may be GSM/EDGE radio access network (GERAN), the second radio access technology It may be a Universal Terrestrial Radio Access Network (UTRAN) and the RSCP threshold may be a UTRAN RSCP threshold, the signal may be a GERAN signal and the received signal may be a GERAN received signal. Additionally, the cell reselection block may determine whether the first and second reselection criteria are suitable for a UTRAN cell and, if so, reselect the UTRAN cell by the mobile station. Further, the UTRAN RSCP threshold includes a hysteresis value or can be defined using the power capability of the mobile station. Still further, the mobile station includes: memory for storing the UTRAN RSCP threshold, ratio and offset.

According to a seventh aspect of the present invention, a system using cell reselection from GSM/EDGE Radio Access Network (GERAN) to Universal Terrestrial Radio Access Network (UTRAN), comprising: Supported by the access network to provide threshold signals indicating applicable thresholds for UTRAN RSCP; serving GERAN cells, supported by the GSM/EDGE radio access network; UTRAN cells, supported by the Universal Terrestrial Radio Access Network; and mobile stations , in response to a threshold signal indicating a UTRAN RSCP applicable threshold, for establishing a reselection criterion for reselecting a UTRAN cell from the serving GERAN cell, wherein the reselection criterion includes at least one threshold, the threshold including a UTRAN RSCP applicable threshold Add the offset defined by the mobile station using predetermined criteria.

Further according to the seventh aspect of the present invention, the mobile station may determine whether reselection criteria are suitable for a UTRAN cell and, if so, reselect the UTRAN cell by the mobile station.

According to an eighth aspect of the present invention, a system using cell reselection from GSM/EDGE Radio Access Network (GERAN) to Universal Terrestrial Radio Access Network (UTRAN), comprising: Supported by the network; mobile station, responding to a GERAN signal indicating the UTRAN RSCP threshold and the ratio of the energy received from the common pilot channel (CPICH) per PN chip to the total power spectral density received at the mobile station antenna connector An offset of (Ec/No) used to establish first and second reselection criteria for reselecting the UTRAN cell, wherein the first reselection criterion includes a threshold comprising the ratio (Ec/No ) plus an offset added to the ratio by the mobile station, and the second reselection criteria include the UTRAN RSCP threshold; and the serving GERAN cell (20-1-A), supported by the GSM/EDGE radio access network, for providing the GERAN signal, wherein the mobile station reselects from the serving GERAN cell to the UTRAN cell if the mobile station determines that the first and second reselection criteria are appropriate for the UTRAN cell.

According to a ninth aspect of the present invention, a cell reselection capable of performing cell reselection from a serving GERAN cell supported by a GSM/EDGE Radio Access Network (GERAN) to a UTRAN cell supported by a Universal Terrestrial Radio Access Network (UTRAN) An integrated circuit, including: a receiving/transmitting/processing module, responsive to a threshold signal indicating the UTRAN RSCP applicable threshold from the UTRAN cell supported by the Universal Terrestrial Radio Access Network, for providing an indication of the UTRAN RSCP applicable threshold a received threshold signal; and a cell reselection block, responsive to the received threshold signal indicating the UTRAN RSCP applicable threshold, for establishing reselection criteria for reselecting a UTRAN cell from the serving GERAN cell, wherein the reselection The selection criteria include at least one threshold, which includes the UTRAN RSCP applicable threshold plus an offset defined by the cell reselection block using predetermined criteria.

According to a tenth aspect of the present invention, a system capable of performing cell reselection from a serving GERAN cell supported by the GSM/EDGE Radio Access Network (GERAN) to a UTRAN cell supported by the Universal Terrestrial Radio Access Network (UTRAN) An integrated circuit mobile station comprising: a receiving/transmitting/processing module responsive to a GERAN signal from a serving GERAN cell indicating the UTRAN RSCP threshold and the energy received from the Common Pilot Channel (CPICH) per PN chip in relation to the mobile an offset of the ratio (Ec/No) of the total power spectral density received at the station antenna connector for providing the received GERAN signal indicating the UTRAN RSCP threshold and the offset of the ratio; and a cell reselection block, Responsive to the received GERAN signal indicating the UTRAN RSCP threshold and the offset of the ratio, for establishing first and second reselection criteria for reselecting the UTRAN cell from the serving GERAN cell, wherein the first reselection The criteria include a threshold comprising the ratio (Ec/No) plus an offset added to the ratio, and a second reselection criterion comprises the UTRAN RSCP threshold.

An advantage of the first mode of the invention is that virtually the same behavior as proposed by the prior art can be achieved without signaling changes. There is also the advantage that the ability to broadcast system information by GERAN is already mature in the sense that additional new parameters (such as intersystem reselection parameters) may either not be possible, or make some more important if these parameters are still added The expansion of will not be possible in the future.

The advantage of the second mode is that the exact same mobility behavior can be accomplished with proposed improvements to the existing technology, but in addition the network is able to properly control legacy terminals (those that only comply with existing reselection rules) as well as new terminal. Usually the CPICH Ec/No threshold should be set quite high for legacy terminals to avoid mobile stations being periodically reselected to unloaded UTRAN cells, while new mobiles can use a more aggressive Ec/No threshold (since it is determined by controlled by this new RSCP threshold without risk of uplink failure).

In addition, the method of the present invention is also more accurate since the uplink failure will depend on the output power capability of the mobile station. In the preferred case where the mobile station has higher output power capabilities, a lower RSCP threshold will be accepted.

Description of drawings

For a better understanding of the nature and objects of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings, in which:

1 is a system block diagram showing an embodiment of cell reselection from a GERAN cell to a UTRAN cell by a mobile station according to the present invention;

FIG. 2 is a flowchart illustrating an embodiment of cell reselection from a GERAN cell to a UTRAN cell by a mobile station according to the present invention; and

Fig. 3 is a flowchart showing another embodiment of cell reselection by a mobile station from a GERAN cell to a UTRAN cell according to the present invention.

Detailed ways

The present invention provides a new method for cell reselection by a mobile station from a serving GERAN cell supported by the GSM/EDGE Radio Access Network (GERAN) to a UTRAN cell supported by the Universal Terrestrial Radio Access Network (UTRAN) .

According to the first embodiment of the present invention, the involved inter-system reselection behavior is realized without signaling changes. In the first embodiment of the present invention, the advantage is that the threshold for inter-system reselection is realized by using target UTRAN cell applicable criteria. Whenever reselection is triggered by existing reselection parameters, the mobile station needs to read the system information of the target cell, firstly to evaluate the applicable criteria on the cell. According to the invention, for any reselection attempt where the reselection is first triggered but the target cell criteria fails, the mobile station will store the RSCP criteria (or UTRAN RSCP criteria) for that particular cell. This value (i.e. the RSCP applicable threshold), optionally modified with an offset (e.g. using a hysteresis value or taking into account the mobile station's power capabilities), can then be used as Additional reselection criteria for selecting other UTRAN cells to be evaluated. The offset (eg the hysteresis value) may be fixed by a standard in order to avoid signaling changes, or alternatively new parameters may be added or other possible hysteresis parameters may be used for this purpose.

Typically, reselection criteria are updated periodically so that the mobile station is made aware of new values if the network starts broadcasting modified values. Applicability to stored UTRAN values may be limited to the same period of time but the preferred validity may be time dependent. The likelihood of change is small and performance degradation will be limited if the mobile station continues to use (once read) UTRAN parameter values after the broadcasted value has changed (this phenomenon has occurred today for a limited period of time). A relatively long valid time period will generally allow the mobile station to avoid repeatedly reading parameters from the same candidate cell because the mobile station may be moving to a certain area of other cells. The preferred validity trigger would still be event based, like reselection or location area change. According to a second embodiment of the invention, the flexibility of signaling changes is used as an advantage. In a second embodiment of the invention, not only a threshold compared to UTRAN CPICH RSCP is added to the reselection criteria, but additionally, an offset to UTRAN CPICH Ec/No is also added by those supporting the new UTRAN RSCP threshold The mobile station is used for reselection evaluation. In addition, unlike the prior art, the present invention proposes to consider the hysteresis and/or mobile station output power capability as the RSCP acceptance criteria in order to properly handle mobile stations with different output power capabilities.

Therefore, in a first embodiment, additional memory for the UTRAN RSCP applicable threshold for a certain number (at least one) of UTRAN cells needs to be implemented in the mobile station. In the second embodiment, the mobile station needs to be upgraded to support the new reselection parameters.

1 is one of many other examples of a system block diagram illustrating an embodiment of cell reselection by a mobile station 10 from a GERAN cell to a UTRAN cell according to the present invention.

In the example of FIG. 1 , the mobile station 10 includes a cell reselection block 14 , a memory 12 and a transmission/reception/processing module 16 . The cell reselection block 14 is a key block for implementing the present invention and all steps performed by the mobile station 10 involving the cell reselection can be coordinated and initiated by the cell reselection block 14 .

According to the invention, this block 14 can be implemented as a software or hardware block or a combination thereof. Additionally, the block 14 may be implemented as a separate block or may be combined with any other standard block of the mobile station 10 . The cell reselection block 14 can use the memory 12 to store and retrieve the corresponding cell information described in the present invention. Furthermore, the memory 12 can be implemented in various ways. It may be part of the general memory of the mobile station 10 or it may be a separate dedicated area (eg Subscriber Identity Module (SIM), etc.). Finally, the mobile station 10 comprises a transmission/reception/processing module 16 which can be implemented in various ways, which are well known in the prior art. In general, modules 16 may include transmitters, receivers, CPU and I/O blocks, and the like. Basically, the module 16 is used to provide effective communication between the cell reselection block 14 and the network, which will be described in detail below.

FIG. 1 shows at least two subnetworks 20 - 1 (GERAN type) and 20 - 2 (UTRAN type) in a radio sensitive geographical area 24 for the mobile device 10 . Each of the two subnetworks 20-1 and 20-2 includes a certain number of cells, for example, the subnetwork 20-1 includes N cells 20-1-1, . . . 20-1-A, .. .20-1-N and the subnetwork 20-2 comprise N cells 20-2-F, ... 20-2-A, ... 20-2-N. According to the detailed description made in relation to FIGS. 2 and 3, the mobile station 10 may, for example, be camped on a serving GERAN cell (e.g., cell 20-1-A) of the subnetwork 20-1, camping on the subnetwork 20 -2 on the UTRAN cell evaluated for reselection (e.g. cell 20-1-B), or camping on a previously selected (before selection of the serving cell 20-1-A) UTRAN cell 20-1-F .

The network 38 typically includes a network provider (or network operator) 26 that provides, for example, the serving GERAN cell 20-1-A with a cell list signal 33 (in the context of the present invention), the cell list signal comprising List of cells (both GERAN cells and UTRAN cells) evaluated for reselection in the GERAN cell 20-1-A.

Fig. 2 shows the implementation of cell reselection performed by the mobile station 10 from a GERAN cell (such as a serving cell 20-1-A) to a UTRAN cell (such as a UTRAN cell 20-1-B) according to the present invention way flow chart.

The flowchart of FIG. 2 depicts only one possible scenario among many others. In the method according to the first embodiment of the invention, in a first step 40, the mobile station (MS) 10 camps on or "visits" the UTRAN cell (or previous UTRAN cell) 20-1-F and detects (read) the applicable standard. In particular, the receiving/transmitting/processing module 16 provides an indication to the cell reselection block 14 in response to a threshold signal 31 (see FIG. 1 ) indicating a UTRAN RSCP applicable threshold from the UTRAN cell 20-1-F The received threshold signal 22 (see FIG. 1 ) exceeds the UTRAN RSCP applicable threshold.

In a next step 42, the MS 10 stores RSCP applicable parameters (ie as UTRAN RSCP applicable thresholds) for subsequent use (eg stores UTRAN RSCP applicable thresholds in the memory 12). If the UTRAN applicable standard is not suitable for the UTRAN cell 20-1-F, then in the next step 46, the MS selects the GERAN cell 20-1-A. In a next step 48, the MS 10 (i.e., the cell reselection block 14) reads (see corresponding signals 30 and 23 in FIG. Both, pointers and also e.g. about reselection parameters).

In a next step 50, the MS 10 (i.e., the cell reselection block 14) generates an RSCP threshold (or "threshold") modified by an offset from the previously stored UTRAN applicable parameters; Reselection criteria from GERAN cells to UTRAN cells. The offset may include a hysteresis value or may be defined using the power capabilities of the MS 10 (as noted above). In a next step 52, the MS 10 (i.e., the cell reselection block 14) monitors (see corresponding signals 32 and 21 in FIG. 1 ) the UTRAN CPICH RSCP levels of UTRAN neighbor cells (using the Criteria) and CPICH Ec/No (this criterion is defined by prior art) and RXLEV of GERAN neighbor cells (which are selected for evaluation for reselection).

In step 54, it is determined after the reselection evaluation whether the reselection criteria are suitable for UTRAN or GERAN cells. If the reselection criteria (via prior art) are suitable for the GERAN cell, processing goes to step 46 and a new GERAN cell is reselected. However, if the reselection criteria (established in step 50) are suitable for the UTRAN cell (e.g. cell 20-1-B), the process goes to step 40 and a new UTRAN cell may be reselected (see above steps 40).

3 is a diagram illustrating a second implementation of cell reselection by the MS 10 from a GERAN cell (e.g., serving cell 20-1-A) to a UTRAN cell (e.g., UTRAN cell 20-1-B) according to the present invention way flow chart.

The flowchart of Figure 3 depicts only one possible scenario among many others. In the method according to the first embodiment of the invention, in a first step 56, the MS 10 selects the GERAN cell 20-1-A and reads (see corresponding signals 30 and 23 in FIG. 1 ) system information (eg pointers to locally available neighboring cells, both GERAN cells and UTRAN cells, and further relevant reselection parameters). In particular, the receiving/transmitting/processing module 16 is responsive to a GERAN signal 30 (see FIG. 1 ) indicating the UTRAN RSCP threshold and the energy received per PN chip from the Common Pilot Channel (CPICH) relative to the energy received at the mobile station antenna. The offset of the ratio (Ec/No) of the total power spectral density received at the connector, the cell reselection block 14 is provided with said offset received indicating said UTRAN RSCP threshold and said ratio Ec/No The GERAN signal 23 .

In a next step 60, the MS 10 (i.e. the cell reselection block 14) evaluates and generates evaluation criteria based on the UTRAN RSCP threshold and based on the Ec/No threshold modified with the Ec/No offset (thus retaining Flexibility to control this Ec/No threshold separately for new and legacy devices as described above). The UTRAN RSCP threshold may include a hysteresis value or may be defined using the power capabilities of the MS 10 (as noted above).

In the next step 62 (similar to step 52), the MS 10 (i.e. the cell reselection block 14) monitors (see corresponding signals 32 and 21 in FIG. 1 ) the UTRANCPICH RSCP levels of UTRAN neighbor cells (using step Criteria established in step 60) and CPICH Ec/No (using the criteria established in step 60) and RXLEV of GERAN neighbor cells (which are selected for evaluation for reselection).

In step 64, it is determined after the reselection evaluation whether the reselection criteria are suitable for UTRAN or GERAN cells. If the reselection criteria (via prior art) are suitable for the GERAN cell, processing goes to step 56 and a new GERAN cell is reselected. However, if the reselection criteria (established in step 60) are suitable for the UTRAN cell (eg cell 20-1-B), then the process moves to step 66 and a new UTRAN cell may be reselected.

It should be noted that according to the embodiments of the present invention, the inter-system cell reselection described in the present invention can be applied to various emerging radio access technologies and is not specific to existing systems involving GERAN and/or UTRAN based systems. accomplish.

As stated above, the present invention provides both a method and a corresponding apparatus comprising various modules providing the functionality to perform the steps of the method. The module may be implemented as hardware, or as software or firmware for execution by a computer processor. In particular, in the case of firmware or software, the invention may be provided as a computer program product comprising a computer readable storage structure on which computer program code for execution by a computer processor ( That is, the software or firmware).

It should be understood that the arrangements described above are merely illustrative of the application of the principles of the invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the scope of the invention, and the appended claims are intended to cover such modifications and arrangements.

Claims (25)

1. A method for cell reselection, comprising: selecting, by the mobile station, a previous cell supported by the second radio access technology and reading and storing an RSCP applicable threshold from said previous cell; selecting, by the mobile station, a serving cell supported by a first radio access technology; and establishing, by the mobile station, reselection criteria for reselecting from the serving cell a cell supported by the second radio access technology, wherein the reselection criteria include at least one threshold, the threshold including the RSCP A threshold plus an offset defined by the mobile station using predetermined criteria is applied for cell reselection by the mobile station from the serving cell to a cell supported by the second radio access technology. 2. The method according to claim 1, wherein the serving cell is a serving GERAN cell, the cell supported by the second radio access technology is a UTRAN cell, and the previous cell is a previous UTRAN cell, The first radio access technology is a GSM/EDGE radio access network, the second radio access technology is a universal terrestrial radio access network, and the RSCP applicable threshold is a UTRAN RSCP applicable threshold. 3. The method of claim 2, further comprising: It is determined whether said reselection criteria are suitable for said UTRAN cell and, if so, said UTRAN cell is reselected by said mobile station. 4. The method according to claim 2, wherein prior to the step of selecting the serving GERAN cell, the method comprises: Selecting a previous UTRAN cell and reading and storing the UTRAN RSCP applicable threshold from the previous UTRAN cell. 5. The method of claim 2, wherein the offset comprises a hysteresis value or is defined using power capabilities of the mobile station. 6. A method for cell reselection, comprising: selecting, by the mobile station, a serving cell supported by the first radio access technology; and establishing, by said mobile station, first and second reselection criteria for reselecting from said serving cell to a cell supported by a second radio access technology for use by said mobile station from said serving cell to said cell supported by said second radio access technology. Cell reselection is performed on a cell supported by two radio access technologies, wherein the first reselection criterion includes a threshold value including the energy received from the common pilot channel per PN chip and the energy received at the antenna connector of the mobile station The ratio of the total power spectral density received at , plus an offset appended to the ratio by the mobile station, and the second reselection criterion includes an RSCP threshold, provided by the serving cell to the mobile station for the The offset of the ratio and the RSCP threshold, wherein the offset is not appended to the ratio if the mobile station does not support the RSCP threshold. 7. The method according to claim 6, wherein the serving cell is a serving GERAN cell, the cell is a UTRAN cell, the first radio access technology is a GSM/EDGE radio access network, and the second radio The access technology is Universal Terrestrial Radio Access Network and the RSCP threshold is UTRAN RSCP threshold. 8. The method of claim 7, further comprising: It is determined whether said first and said second reselection criteria are suitable for said UTRAN cell and, if so, said UTRAN cell is reselected by said mobile station. 9. The method of claim 7, wherein the UTRAN RSCP threshold comprises a hysteresis value or is defined using the power capability of the mobile station. 10. A mobile station comprising: a receiving/transmitting/processing module, responsive to a threshold signal indicating an RSCP applicable threshold from a previous cell supported by a second radio access technology, for providing a received threshold signal indicating said RSCP applicable threshold; as well as a cell reselection block, responsive to said received threshold signal indicating said RSCP applicable threshold, for establishing a method for reselecting from a serving cell supported by a first radio access technology by said second A reselection criterion of a cell supported by a radio access technology, wherein the reselection criterion includes at least one threshold, and the threshold includes the RSCP applicable threshold plus an offset defined by the cell reselection block using a predetermined criterion. shift. 11. The mobile station of claim 10, wherein the serving cell is a serving GERAN cell, the cell is a UTRAN cell, the previous cell is a previous UTRAN cell, and the first radio access technology is GSM /EDGE radio access network, the second radio access technology is Universal Terrestrial Radio Access Network and the RSCP applicable threshold is UTRAN RSCP applicable threshold. 12. The mobile station of claim 11, wherein the cell reselection block is configured to determine whether the reselection criteria are suitable for the UTRAN cell, and, if so, reselect the UTRAN cell. 13. The mobile station of claim 11, wherein the offset comprises a hysteresis value or is defined using power capabilities of the mobile station. 14. The mobile station of claim 11, wherein the mobile station comprises: The memory is used to store the applicable threshold of the UTRAN RSCP. 15. A mobile station comprising: a receiving/transmitting/processing module responsive to a signal from a serving cell supported by a first radio access technology, the signal indicating the RSCP threshold and the energy received from the common pilot channel per PN chip in relation to the mobile an offset in the ratio of total power spectral densities received at a station antenna connector for providing a received signal indicative of said RSCP threshold and said offset in said ratio; and a cell reselection block, responsive to said received signal indicative of said RSCP threshold and said offset in said ratio, for establishing a method for reselecting from said serving cell by a second radio access technology first and second reselection criteria for supported cells, wherein said first reselection criterion comprises a threshold comprising said ratio plus an offset appended to said ratio, wherein if said mobile station does not support the RSCP threshold, the offset is not appended to the ratio, and the second reselection criterion includes the RSCP threshold. 16. The mobile station according to claim 15, wherein said serving cell is a serving GERAN cell, said cell is a UTRAN cell, said first radio access technology is a GSM/EDGE radio access network, said second The radio access technology is Universal Terrestrial Radio Access Network, the RSCP threshold is a UTRAN RSCP threshold, the signal is a GERAN signal and the received signal is a GERAN signal. 17. The mobile station according to claim 16, wherein said cell reselection block is configured to determine whether said first and second reselection criteria are suitable for said UTRAN cell, and, if they are suitable, to reselect all The above UTRAN cell. 18. The mobile station of claim 16, wherein the UTRAN RSCP threshold comprises a hysteresis value or is defined using power capabilities of the mobile station. 19. The mobile station of claim 16, wherein the mobile station comprises: a memory for storing the UTRAN RSCP threshold, the ratio and the offset. 20. A system using cell reselection from GSM/EDGE Radio Access Network (GERAN) to Universal Terrestrial Radio Access Network (UTRAN), comprising: The previous UTRAN cell, supported by the Universal Terrestrial Radio Access Network, is used to provide a threshold signal indicating the applicable threshold of the UTRAN RSCP; Serving GERAN cells, supported by GSM/EDGE wireless access network; UTRAN cells, supported by the Universal Terrestrial Radio Access Network; and A mobile station, responsive to a threshold signal indicating a UTRAN RSCP applicable threshold, for establishing reselection criteria for reselecting the UTRAN cell from the serving GERAN cell, wherein the reselection criteria include at least one threshold, the The threshold comprises the UTRAN RSCP applicable threshold plus an offset defined by the mobile station using predetermined criteria. 21. The system of claim 20, wherein the mobile station is configured to determine that the reselection criteria are suitable for the UTRAN cell, and, if they are suitable, to reselect the UTRAN cell. 22. A system using cell reselection from GSM/EDGE Radio Access Network (GERAN) to Universal Terrestrial Radio Access Network (UTRAN), comprising: UTRAN cell, supported by the universal terrestrial radio access network; Serving GERAN cells, supported by the GSM/EDGE radio access network, for providing GERAN signals; and a mobile station responsive to a GERAN signal indicating a shift in the UTRAN RSCP threshold and the ratio of energy received from a common pilot channel per PN chip to the total power spectral density received at the antenna connector of the mobile station , for establishing first and second reselection criteria for reselecting the UTRAN cell from the serving GERAN cell, wherein the first reselection criterion includes a threshold value including the ratio plus the an offset appended to the ratio by the mobile station, and the second reselection criterion includes a UTRAN RSCP threshold, wherein the offset is not appended to the ratio if the mobile station does not support the RSCP threshold. 23. The mobile station of claim 11, wherein an integrated circuit comprises the cell reselection block and the receiving/transmitting/processing module. 24. The mobile station of claim 15, wherein an integrated circuit comprises the cell reselection block and the receiving/transmitting/processing module. 25. The system of claim 22, wherein the mobile station is configured to determine whether the reselection criteria are appropriate for the UTRAN cell, and, if appropriate, reselect the UTRAN cell.

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