TWI411326B - Cell change method, manager and controller and related network node and mobile user terminal - Google Patents

Description

Unit change method, manager, controller and related network nodes and user terminals

The present invention relates generally to unit changes for mobile user terminals in a cellular network, and more particularly to mobile user terminals that perform such unit changes for radio transmission resources having multiple simultaneous configurations. .

The function of manipulating the actions of the user terminal is the basic component of the cellular network. From a service quality perspective, such functionality must ensure that as the user moves from one unit to another during an active session, service continuity can be maintained and each new session can be established in a sufficiently good radio environment. From a spectrum efficiency standpoint, such functionality should ensure that active users are always served by the most appropriate base station or base stations (which typically represent the nearest base station in radio sensing). Programs that modify the number or identification of a base station that is a given user service during an active session are collectively referred to as (service) unit changes or "delivery."

Providing diversity for fading is a key method to improve the performance and efficiency of a cellular network. However, there are many macrodiversity techniques that focus on mitigating the effects of Rayleigh fading. Examples include receiver diversity, transmit diversity, interleaving, and frequency hopping. Macrodiversity to combat the effects of shadow fading has fewer options. In order to obtain macro diversity gain, the possibility of transmitting and/or receiving relevant information simultaneously in different base stations must be involved in some way. Macrodiversity is particularly advantageous near cell boundaries where macrodiversity can greatly improve service coverage, especially when shadow fading from different base stations is uncorrelated.

A multi-carrier system utilizes multiple radio transmission resources to transmit data to and/or receive data from a given user terminal. Multi-carrier generally means that multiple carrier frequencies are used, but more generally it can include all systems, where multiple radio transmission resources can be simultaneously configured to a given user terminal. Examples of radio transmission resources well known in the art are frequency, time slot, orthogonal frequency division multiplexing (OFDM) blocks, channelization codes, and the like.

In existing cellular systems that include multi-carrier systems, the handover procedure is generally classified as "hard" handover or "soft" handover. The hard handover procedure is schematically illustrated in Figures 1A through 1C for a multi-carrier system. In FIG. 1A, the mobile user terminal 10 appearing in a unit 25 of the serving base station 20 has two radio transmission resources 22, 24 that are simultaneously configured to perform uplink and downlink communications with the base station 20. The mobile user terminal 10 then begins to move away from the serving base station 20 and into one of the units 35 of the other base station 30. FIG. 1B illustrates a situation in which the mobile terminal 10 appears in the coverage area of the two units 25, 35. At this location, the resources 22, 24 configured by the old base station 20 are still used for communication. If the move is continuing, as in the case shown in Figure 1C, the single serving base station 20 is transferred in its entirety to the other serving base station 30 on the connection. The mobile user terminal 10 then has two radio transmission resources 32, 34 configured to communicate with the new base station 30.

The soft handover system in a multi-carrier system is schematically illustrated in Figures 2A through 2C. In FIG. 2A, a mobile user terminal 10 has been configured with two radio transmission resources 22, 24 for uplink or downlink communication with the base station 20. The mobile user terminal begins to move away from the unit 25, which is currently served by the active base station, and moves into the new unit 35 of the new base station 30, see Figure 2B. In this example, two radio transmission resources 32, 34 are also simultaneously configured for the user terminal 10 to communicate with the new base station 30. This means that the so-called active set of one of the plurality of base stations 20, 30 remains in simultaneous connection 22, 23, 32, 34 with the mobile user terminal 10. The replicated information is always transmitted and/or received simultaneously in the plurality of base stations 20, 30 using the individually configured resources 22, 24 and 32, 34. This means that the same original (bit) data is transmitted on the resources 22, 24 and 32, 34 of the two different units 25, 35, although different physical layer processing can be used in the two units 25, 35, for example The original data is disturbed. As the mobile user terminal 10 continues to move into the new unit 35, see Figure 2C, the old base station 20 is removed from the active set and the configuration of its resources 22, 24 is revoked. The user terminal 10 then has only two simultaneously configured radio transmission resources 32, 34 available for data communication.

Another uncommon handover method that can be considered as a hybrid handover between soft handover and hard handover is "fast handover". It is similar to soft handoff because one of the plurality of base stations is likely to be active, but only one of the base stations in the active centralized set actually transmits or receives the selection of the active base station based on the instantaneous radio conditions at any point in time.

Soft handoff and fast handoff solutions generally provide better service coverage and a more stable handover procedure than hard handoff because they inherently contain macro diversity gains because they are sent simultaneously in multiple base stations. And/or receive relevant information (in this case, copy information). However, it involves higher complexity and cost in terms of infrastructure and user terminals, and it requires more transmission and null intermediation resources (the amount of resources allocated to the terminal during the handover will double). Its introduction is completely unfeasible under any circumstances.

Hard handoff is relatively easy and cheaper to implement and it utilizes less resources than soft handoffs and fast handoffs, but achieving the necessary stability and service coverage may be difficult due to the lack of macrodiversity.

An example of the difficulty of service coverage experienced by hard handover may occur when performing a unit change during file download or similar data transfer. The data already used in the buffer for the source unit may need to be emptied before the handover can be performed, which delays the handover procedure or is discarded and then resent in the target unit. Service quality and system performance are adversely affected in any way.

There is therefore a need for a solution for unit change and handover that can be used in hive systems where soft handover and fast handover are not feasible or undesirable, and which maintains handover stability and service coverage.

The present invention overcomes these and other shortcomings of prior art configurations.

It is a general object of the present invention to provide a unit change program that enables macrodiversity to be provided.

Another object of the present invention is to provide a unit change procedure that is low cost and complex in terms of receiver and transmitter equipment.

Another object of the present invention is to provide a unit change or handover procedure suitable for use in a multi-carrier communication system.

These and other objects are met by the present invention as defined by the scope of the appended claims.

Briefly, the present invention relates to a unit change or handover procedure that can be used in a multi-carrier system in which a mobile user terminal has a service that is simultaneously configured to have a service unit in which one of the user terminals currently appears Multiple radio transmission resources for base station communications. The unit change of the present invention is performed in order (ie, step by step), so that when the user terminal moves away from the current unit and moves into a new service unit, a configuration is provided to the user terminal to serve a base for the new service unit. The radio transmission resources of the station communication replace a plurality of simultaneously configured radio resources. Therefore, not all resources allocated to the user terminal are replaced or handed over at the same time. Instead, this resource replacement is performed in at least two steps, replacing a first set of radio transmission resources in the first step and replacing the remaining resources in one or more subsequent (time separation) steps.

As the mobile user terminal moves throughout the system, the network nodes within the communication range of the terminal and/or base station and the terminal preferably perform measurements and estimation related to radio quality. These measurements and estimates are used to detect the need for a unit change, i.e., to detect when the unit change procedure of the present invention is initiated. The decision to trigger a unit change may be made by a user terminal, a current serving base station, a neighboring base station or a control network node in the system as a candidate base station of the new service base station, based at least in part on Quality measurement. A control message is typically generated and assigned to the associated base station and preferably to the user terminal after the detection of the changed requirements of the unit. The parties involved in the control message command are in a sequential replacement of the radio transmission resources that trigger and perform the present invention.

In a typical example, an active user appears in the first unit and is served by the first base station. The user terminal further has N radio transmission resources configured to communicate with the base station. The resources may be N uplink resources used to transmit data to the base station or N downlink resources used to receive data from the base station, where N 2. The present invention contemplates that the terminal device can be configured with N ₁ downlink resources and N ₂ uplink resources, where at least one of N ₁ and N ₂ is equal to or greater than 2. The unit change procedure can be triggered as the mobile user terminal moves away from the first base station and enters the second unit with the second serving base station. The N(N ₁ and N ₂ ) resources are then replaced in sequence by resources configured to the user terminal to communicate with the second base station in the new second unit.

The unit change procedure of the present invention can also be applied to so-called in-site handover. This means that after the unit change is completed, as before the change procedure is initiated, the user terminal is served by the same base station and communicates with the base station. However, the user terminal appears in a different unit or sector of the base station before or after the unit change.

More than two base stations and units may be involved in the unit change procedure, which means that when the start unit changes, the user terminal sets the radio resources in different units during and/or after the unit change. Connect to and communicate with multiple base stations. This represents a very flexible aspect of the present invention in terms of specific network layout and communication scenarios that may benefit from the present invention. The basic requirement, however, is that the user terminal has a plurality of radio transmission resources configured simultaneously to communicate with at least one base station, and the resources are configured to be replaced by resources allocated to the terminal to communicate with the at least one base station.

In another embodiment of the invention, the mobile user terminal enables multiple radio transmission resources to be simultaneously configured to communicate in at least two different units and to communicate with two different base stations or one same base station. In addition, the data transmitted by the mobile user terminal or received by the terminals in two different units is based on different original data. The plurality of initially configured resources are then replaced in sequence by resources used by the mobile user terminal to communicate with one or more base stations.

The present invention also provides flexibility in using radio transmission resources during a unit change procedure. In a first possible implementation, resources in different units and configured for the same user terminal can be used to transmit data associated with the physical layer (uplink/downlink). For example, different channel codes can be used to send the same user profile on the resource. Alternatively, the user data may be transmitted using the radio transmission resources configured in the first unit, and the resources allocated to the terminals in the second unit may be used to transmit additional redundant data, for example in the form of additional parity bits. data. In an alternative, the radio transmission resources are used to transmit data in the first and second units, which are associated with higher layers but are not related to the physical layer. For example, a user terminal can request to use a resource to download a web page. In this case, items belonging to this same web page can be provided on different radio transmission resources. This represents a macro diversity gain with a higher layer aspect but no direct gain in terms of link performance. The user plane and control plane can be handled differently in this respect. For example, user plane resources in the first and second units may be used to transmit data unrelated to the physical layer to maintain user data output throughout the handover, while control plane resources in the first and second units may be used to transmit Information directly related to the same control plane signaling to maximize the stability of the signaling link.

Since the present invention relates to the replacement of radio transmission resources in multiple steps and may involve multiple different base stations, there is a greater degree of flexibility in how to perform actual resource replacement. Therefore, resource replacement can be performed according to different substitution criteria for obtaining the best possible unit change procedure. These criteria can be used to determine, for example, what resources will be replaced in each step, when such substitutions will occur, how many steps should be involved in the unit change, and what new resources are to be deployed to the user terminal.

An example of such a substitution criterion is the actual value of one of the timers associated with a unit change. Each step of resource replacement can be performed, for example, after a predefined period of time after detecting a need for a unit change. Alternatively, a minimum/maximum time period can be utilized between the two substitution steps in the unit change procedure. In another example, a quality parameter can be used that represents the radio quality of the communication link between the mobile user terminal and the original base station. For example, it may be more advantageous to replace more resources in the first substitution step under conditions in which the radio quality is rapidly degraded as compared to the case where the link quality is degraded more slowly. Accordingly, a radio quality metric can be used as a replacement criterion that represents the radio quality of the mobile subscriber terminal in at least one destination unit that is moved in. If the quality (eg, received signal strength) increases slowly, the unit change procedure can advantageously be extended over time, for example by using more than two substitution steps (where applicable) and/or adding two substitution steps. The time period between executions. The buffer level in the transmit buffer configured in the current serving base station and including data for the user terminal can also be used as a replacement criterion in accordance with one of the present inventions. If the base station has a large amount of data to transmit to the user terminal shortly before the start unit change, it is generally advantageous to keep as much downlink transmission resources as possible from the base station configuration until the base station has emptied the buffer. This information. This means that in the first step or in a few steps, instead of a single downlink resource, instead of replacing multiple resources in the first (minor) step. In a similar manner, the buffer levels in the user terminal, a candidate serving base station, and/or a control network node can be associated with unit change operations.

The present invention provides the following advantages: - providing macro diversity without introducing cost and complexity into the infrastructure and soft handover and fast handover terminals, and requiring less transmission and null intermediation resources than soft handover and fast handover; Provides enhanced service coverage and handover stability compared to hard handover; - can be easily combined with other techniques to improve handover performance (eg unit muting); - provides flexibility in the replacement of radio resources in sequence • Provides faster and less divisive handover procedures when the old service base station has buffered data for the user terminal when the boot unit changes; and – maximizes system capacity and performance.

Other advantages provided by the present invention will be apparent upon reading the following description of various embodiments of the invention.

In all figures, the same reference characters will be used for corresponding or similar elements.

The present invention relates to unit changes for mobile user terminals in a cellular network or system, and more particularly to performing such unit changes for mobile user terminals having multiple simultaneously configured radio transmission resources. machine.

The unit change program according to the present invention comprises any program in which a mobile user terminal moves from one of the at least one (service) unit radio coverage areas to one of the at least one new unit radio coverage areas. In the unit change procedure, the base station is used by the user terminal to communicate with at least one of the current units by configuring a radio transmission resource for the mobile terminal to communicate with the base station of the at least one new unit. Radio transmission resources for communication. This means that the expression "unit change" procedure of the present invention is widely used and includes procedures indicative of handover, unit change, and unit reselection in the art.

The present invention is applicable to communication systems in which a mobile user terminal has multiple (i.e., at least two) radio transmission resources that are simultaneously configured to communicate with a current serving base station. Such communication systems are generally indicated as multi-carrier systems in which multiple radio transmission resources are configured to transmit data to and/or receive data from a given user terminal. Examples of radio transmission resources that may be used to transmit data on a radio interface in a multi-carrier system of the present invention are frequency, time slot, orthogonal frequency division multiplexing (OFDM) blocks, and channelization codes.

Radio transmission resources are conceivable to divide the total radio resources into orthogonal (ie non-overlapping) pieces. Ideally, using different radio transmission resources simultaneously does not cause any interference between resources. In practice, some interference may occur due to the difficulty or expense of complete isolation of radio transmission resources. Examples include power leakage into adjacent frequencies, loss of channelization code orthogonality in time-distributed channels, and the like. In particular, the present invention is suitable for mapping a logical data stream associated with a mobile user terminal to a plurality of radio resource units. A logical data stream contains data having similar purposes and characteristics, such as paging information or user data.

Utilizes hard handover and service coverage and delivery in the Global System for Mobile Communications (GSM), which includes the General Packet Radio Service (GPRS) and its Enhanced Data Rate (EDGE) technology for GSM development to Enhanced GPRS (EGPRS) Handing stability is a challenge in commercial networks. The unit change procedure of the present invention will improve these two areas without introducing the cost and impact of soft handover or fast handover. In (E)GPRS, multiple radio transmission resources are now simultaneously configured in a plurality of time slots on a frequency to a logical data stream of a given user terminal, such as a Temporary Block Flow (TBF). The frequency can be changed by time in accordance with a frequency hopping sequence, but the same user terminal does not utilize multiple frequencies on the same link at the same time. In addition to multiple time slots, GPRS and EGPRS can be expanded to allow multiple frequencies to be used simultaneously. The invention is therefore applicable to GSM systems with GPRS and EGPRS.

OFDM is likely to be a key radio technology in the long-term development of cellular networks. In OFDM, the radio resources in terms of spectrum and time are divided into "blocks" which contain a certain number of OFDM subcarriers (frequency) and OFDM symbols (time). A resource block is a minimum radio transmission resource that can be scheduled for a user, and it is desirable to simultaneously send multiple blocks to a single user in a single logical data stream in a common manner.

It may be necessary to avoid the cost and complexity of soft handover and fast handover in future cellular networks without compromising service coverage and handover stability. Accordingly, the present invention can be advantageously implemented in an OFDM-based communication system in which an OFDM block is a radio transmission resource configured for a user terminal.

Most channels in a code division multi-way proximity (CDMA) system utilize soft handoff, and thus the performance benefits of implementing the invention in a CDMA based system for such channels are likely to be limited. However, channels that do not use soft handoff, such as High Speed Downlink Shared Channel (HS-DSCH) in High Speed Downlink Packet Access (HSDPA), may benefit from the unit change procedure of the present invention. In this case, a plurality of radio transmission resources simultaneously allocated to a predetermined user terminal are channelization codes.

As already mentioned above, the unit change procedure of the present invention is applicable to a multi-carrier system in which a user terminal has a plurality of radio transmission resources simultaneously configured to communicate with a base station or another communication network node. The plurality of radio transmission resources may be downlink resources, that is, resources used by the base station to transmit data to the user terminal. In an alternate embodiment, the plurality of resources are uplink resources used by the user terminal to transmit data to the base station. The present invention also contemplates that a portion of the radio transmission resources available to the user terminal can be downlink resources, while the remainder of the available resources are uplink resources. In this case, the user terminal having a configuration for uplink communication with the base station radio transmission resource the N ₁ and N are configured to perform downlink communication with the base station _two radio transmission resources. In a specific embodiment N ₁ =N ₂ 2 and in another embodiment N ₁ ≠ N ₂ and at least one of N ₁ , N ₂ is equal to or greater than 2.

In addition, the user terminal may of course have radio transmission resources configured to communicate with a base station associated with another unit.

The unit change method of the present invention can be considered as a mixture between the previously disclosed soft and hard handover procedures (see FIGS. 1A to 1C and FIGS. 2A to 2C) and thus is indicated herein as phase handover. This phase handover of the present invention has the advantage of soft handoff in terms of macrodiversity but provides this macrodiversity without introducing the cost and complexity of soft handoff. This means that with the cost and complexity in the same category as provided by hard handover, high service coverage and handover stability in the same category as provided by soft handover can be obtained.

3 is a flow chart of a unit change method in accordance with an embodiment of the present invention. The method begins in an optional step S1 in which radio parameters are measured. This radio parameter measurement is performed as a basis for determining whether a unit change is required and should be initiated. Radio parameter measurements can be performed in accordance with prior art techniques. This means that the radio quality measurement can be performed by the user terminal to obtain a link quality metric representing the quality of the radio link between the user terminal and the current serving base station and/or the neighboring base station. The most widely used link quality metric in this context is either the received signal strength or carrier-to-interference (C/I) ratio (or related measurement). In such cases, the user terminal estimates the signal strength or C/I based on signals received from the current serving base station and/or neighboring base stations.

Correspondingly, the radio measurement of step S1 can also be performed by the current serving base station, preferably based on signals received from the user terminal and/or other base stations and/or by neighboring base stations.

The present invention also contemplates that other radio parameters other than the radio link quality metric can be measured in step S1, including, for example, measuring or estimating unit loads in the current unit and/or neighboring units.

The measurements or estimates performed in step S1 may be performed continuously by the relevant units (user terminals and/or base stations) periodically, intermittently, at predefined time instances and/or according to requests for measurement data.

From the above description, it should be understood by those skilled in the art that the specific radio parameters measured or estimated are not critical to the applicability of the present invention, and any radio parameters utilized in the technique can be used in accordance with the invention in this step S1. Contains radio link quality and unit load parameters. Accordingly, the units performing the measurement of the parameters are also inconclusive for the present invention. However, it is preferred to select a radio parameter to be measured and perform the measurements by each unit in a manner that results in an effective unit change in the appropriate unit involved in initiating the unit change and selection procedure at an appropriate time instance. program.

In any case, the radio parameter measurements and estimates are used to determine at step S2 whether a unit change procedure should be initiated. This means that in this step S2, it is detected, at least in part, based on the measured radio parameters whether a given mobile terminal device requires a unit change.

Corresponding to the above description regarding the execution of the radio parameter measurement, it is not critical for the present invention to decide whether to activate the actual unit of a unit change in step S2. This means that the unit can be executed by the user terminal itself, the current serving base station, the neighboring base station, the control network node connected to the service/adjacent base station, or jointly by at least two of the mentioned units. Detection of changed needs.

This detection of the need for unit change in step S2 can be achieved, for example, by comparing the estimated signal strength of the radio link between the user terminal and the serving base station to a quality threshold. If the current signal strength is below the minimum threshold, a unit change requirement may occur. Correspondingly, if the signal strength received by the user terminal from a neighboring unit, or the difference in signal strength between a neighboring unit and the current serving unit exceeds a threshold, the unit change can be initiated. This threshold-based detection of the need for unit changes can of course be applied to other measured radio parameters in addition to the received signal strength.

If a unit change is not actually needed in step S2, the method returns to step S1 where a new quality measurement is performed. This means that the loop represented by steps S1 and S2 is preferably performed in the entire ongoing communication session involving the user terminal. If a need for a unit change is detected in step S2, the method continues to step S3.

In the first specific embodiment of step S3, the unit change is performed by sequentially (ie, stepwise), thereby configuring the user terminal to communicate with at least one base station having a unit different from one of the current units. The radio transmission resources replace the plurality of radio transmission resources allocated to the mobile user terminal to communicate with the current base station in the current unit. This means that the radio transmission resources that are simultaneously configured to the user terminal are modified in order rather than abruptly. This is in sharp contrast to prior art soft and hard handoffs and fast handoffs in which all radio resources are jointly replaced, copied or handed over in a single step. By switching to the radio resources in the new serving base station in each step instead of abrupt switching, macro-diversity can be provided without introducing the cost and complexity of soft handover and fast handover.

The method ends once the required number of multiple transmit resources have been replaced in order.

In this embodiment, instead of one of the steps, the mobile user terminal has at least one first radio transmission resource configured for a first base station associated with a first unit, and simultaneously configured to be different from One of the first units is associated with the same first base station in the second unit or at least one second radio transmission resource configured for a second different base station associated with a second unit. Therefore, the mobile user terminal has a plurality of resources configured at the same time, but at least two of the plurality of resources are arranged in different units. In addition, the original (bit) data transmitted by the user terminal or the first base station using at least the first radio transmission resource is different from at least the second by the user terminal or the first/second base station. The original data sent by the resource. Thus, in sharp contrast to prior art soft handoffs, the first and second resources are not used to simultaneously transmit the replicated material. It is well known to those skilled in the art that data transmitted on a copy resource during soft handover can be processed differently, for example by using different scrambling codes in the two involved units. However, the unprocessed raw material sent on the replicated resource in the prior art soft handoff is always the same.

In step S3, at least the first and second radio transmission resources are sequentially replaced with radio communication resources configured to the user terminal to communicate with the at least one base station. The at least one base station may be a third base station having a third associated unit, the first or second base station having a third associated unit or actually having an associated first or second unit The first or second base station.

The present invention contemplates that the sequential resource replacement of the present invention may involve a number of replacement steps than the number of multiple radio transmission resources configured for the user terminal. For example, if an mobile user terminal has two radio transmission resources configured to communicate with the first base station in the first unit, the configuration may be applied to the user terminal and the second in the first replacement step. The second base station communication resource in the unit replaces the first resource. In the next step, instead of the resources configured in the first replacement step, resources configured to communicate with the user terminal to communicate with, for example, the second base station (but in the third unit associated with the second base station) Resources. The last resource configured in the first unit can then be configured in a third replacement step, and another resource can be configured to the user terminal in the third unit to communicate with the base station.

Thus, the phase handover of the present invention is very flexible to manipulate situations in which a mobile user terminal passes through a communication system and becomes (temporarily) connected to different base stations and (temporarily) appears in different units.

4A through 4C are diagrams illustrating a portion of a communication system 1 using a unit change program in accordance with an embodiment of the present invention. In Fig. 4A, system 1 has been illustrated as having two base stations 20, 30 having two different radio coverage areas or units 25, 35, wherein the base stations provide communication services for the use of connections Terminal 10. In this illustrative example, a mobile user terminal 10 appears in the first unit 25 managed by the first base station 20. The user terminal 10 has, without limitation, two simultaneously configured parallel radio transmission resources 22, 24 that can be used to transmit data to the base station 20, or in an alternative embodiment to receive material from the base station 20. The configuration of the plurality of resources 22, 24 is typically performed by a base station 20 or a control network node 90 (represented by a base station controller (BSC) in the figure) connected to the base station 20.

The mobile user terminal 10 begins to move away from the first base station 20 and approach the second base station 30. During this movement, the user terminal 10 and/or the base stations 20, 30 perform radio quality measurements. The user terminal 10, one of the base stations 20, 30 or the BSC 90 then uses these measurements to decide when to trigger a unit change procedure or phase handover in accordance with the present invention.

Once the phase handover procedure is initiated, the configuration of one of the radio transmission resources 22 in the first unit is revoked because a new radio transmission resource 32 is configured in the second unit to the user terminal, as illustrated in Figure 4B. . This indicates that in this example, the user terminal 10 has one radio transmission resource 24 configured in the first unit 25 and one resource 32 configured in the second unit 35.

Different schemes can be used for the radio resources 24, 32 in the first unit 25 and the second unit 35 during phase handover. In a first possible implementation, resources 24, 32 in different units 25, 35 and configured for the same user terminal 10 can be used to transmit data associated with the physical layer (uplink/downlink). For example, the same user (original bit) data can be sent on two resources 24, 32 using different channel codes. Alternatively, one of the radio transmission resources 32 can be used to transmit user data, while another resource 24 can be used to transmit additional redundant data, such as data in the form of additional parity bits. In both cases, the data transmitted on the two radio resources 24, 32 is based on common information and reaches the direct coding gain on the physical layer. The expression "based on common information" includes the case where the same material is transmitted on two resources 24, 32, although it may be delayed in time, or another resource 24 is used to transmit at least one of the transmitted data including one of the resources 32 Part of the information package. In addition, redundant material is considered to be based on common information in accordance with the present invention.

In an alternative, the radio transmission resources 24, 32 are used to transmit data in the first unit 25 and the second unit 35, which are associated with higher layers but not with the physical layer. In such cases, the data may be associated with the data link layer, the network layer, the transport layer, the session layer, the presentation layer, and/or the application layer. For example, user terminal 10 may request the use of resources 24, 32 to download a web page. In this case, items belonging to this same web page can be provided on different radio transmission resources 24,32. This represents a macro diversity gain with a higher layer aspect but no direct gain in terms of link performance.

The data transmitted in the communication system 1 can be logically divided into a user plane and a control plane. The user plane data is information that is interesting from the user's point of view, that is, the information that the user wants to transmit. The control plane data bearer system internally controls the sending of a message, such as radio resource management. An example of a control plane signaling is a report of the quality of the radio link from the mobile user terminal 10 to the terminal 10 and its serving base station 20 to other nearby base stations 30, and from the network to the terminal. The machine 10 is operative to execute a command to hand over to another unit 35.

The user plane and control plane can be handled differently. For example, user plane resources in the first unit 25 and the second unit 35 may be used to transmit data unrelated to the physical layer to maintain user data output throughout the handover, while in the first unit 25 and the second unit 35 Control plane resources can be used to transmit information directly related to the same control plane signaling in order to maximize the stability of the signaling link.

The transition from the situation in Figure 4A to the situation in 4B thus represents the first step in the sequential resource replacement of the unit change procedure of the present invention. In a second step, the configuration of the remaining resources 24 in the first unit 25 is revoked and the new radio transmission resource 34 is configured to the user terminal 10 in FIG. 4C. These two resources are replaced by two different steps, which are performed in order and thus separated from each other in time. It should also be noted that the same total number of resources 22, 24; 32, 34 are allocated to the user terminal 10 throughout the unit change procedure. In this way, the phase handover is similar to the hard handover procedure and is not compromised by the requirements of more transmission and null intermediaries as required for soft handover. However, even if the total number of resources configured during phase handover does not increase, macrodiversity can be obtained due to this sequential replacement of radio transmission resources.

In Figures 4A through 4C, the mobile user terminal moves from communicating with the first base station in the first unit to communicating with a second different base station in the second different unit. However, the present invention is also applicable to so-called intra-site handover in which a mobile user terminal moves from a first unit or sector managed by a given base station to a second unit or sector managed by the same base station. . This scheme is schematically illustrated in Figures 5A through 5C.

Figure 5A illustrates a portion of a multi-carrier cellular communication system 1 that is associated with and served by a plurality of units, non-limitingly illustrated by three, different sectors or units 25, 35, 45. . The base station 20 receives a first set of radio transmission resources for use in communicating with a user terminal station present in the first unit 25 of its unit, accessing the second resource group for use in the second unit 35, and A third set of resources is accordingly received, which is configured to communicate in the last third unit 45.

In FIG. 5A, the mobile user terminal 10 appears in the first unit 25 served by the base station 20. The user terminal 10 has been configured, without limitation, two radio transmission uplink resources 22, 24 (or two radio downlink resources) to transmit data to (or receive data from) the base station (20). ). The user terminal 10 begins moving toward the second unit 35 managed by the base station 20. At a particular point in the movement, the user terminal 10, the base station 20, or some other network node triggers a change in the unit in accordance with one of the present invention.

Two uplink (or downlink) resources 32 configured for uplink (or downlink) transmissions in the second unit 35 are employed in two (or possibly multiple) steps. 34, the two uplink (or downlink) resources 22, 24 allocated to the user terminal 10 in the first unit 25 are replaced in order. FIG. 5B illustrates a scheme in which one of the radio transmission resources allocated to the user terminal 10 in the first unit 25 has been replaced by the transmission resource 32 configured to the terminal unit 10 in the second unit 35. Accordingly, in the next step, the remaining radio transmission resources of the first unit 25 are replaced by the resources 34 of the second unit 35, see Fig. 5C. Further, in this in-situ unit change procedure, the radio transmission resources are progressively replaced in order, thereby replacing the resources 22, 24 disposed in the first unit 25 by the resources 32, 34 disposed in the second unit 35. The total number of resources configured to the user terminal 10 is changed.

The present invention contemplates that more than two base stations and units may be involved in a unit change procedure in accordance with the present invention. In addition, more than two (parallel) radio transmission resources may be replaced in sequence using radio resources configurable in other units. These aspects are explained in more detail with reference to Figures 6A through 6D.

Figure 6A schematically illustrates a portion of a cellular communication system 1 that utilizes the unit change technique of the present invention. This system 1 has been represented by three units 25, 35, 45, each unit being serviced by a single base station 20, 30, 40. An action use terminal 10 is currently present in the first unit 25 and is in communication with the base station 20 of the first unit 25. Thus, the mobile user terminal 10 has been configured with a plurality (three in this example) of radio transmission resources 22, 24, 26 for this communication.

The user terminal 10 begins to move away from the current serving base station 20 and into one of the areas where the radio coverage of all three units 25, 35, 45 partially overlaps. The need for a unit change is detected at a given instance and the unit change procedure of the present invention is initiated. As illustrated in Figures 6A through 6D, the configured radio resources are replaced in sequence in three steps in this illustrative example. In a first step (see transition from Figures 6A to 6B), one of the resources 22 is replaced by a resource 32 assigned to one of the user terminals 10 in the second unit 35. In this example, user terminal 10 can perform communications with first base station 20 and second base station 30. It is mentioned in the above text that relevant or unrelated material can then be transmitted on the radio resources 24, 26 of the first unit 25 and on the radio resources 32 of the second unit 35.

In the next step, as illustrated in Figures 6B to 6C, the other of the resources 24 of the first unit 25 is replaced by a resource 42, but in this case the resource 42 can be used by the terminal 10 and the third unit 45. The base station 40 communicates. In this example, the mobile terminal 10 has radio transmission resources 26, 32, 42 disposed in each of the three units 25, 35, 45 and is in communication with all three base stations 20, 30, 40. The possibility of introducing macro diversity is more versatile in this case.

The user terminal 10 continues to move away from the first unit 25 and replaces the final resource 26 disposed in this unit 25 by a second radio transmission resource 34 configured to the terminal 10 in the second unit 35 in FIG. 6D. .

All radio transmission resources 22, 24, 26 initially allocated to the user terminal 10 at the beginning of the unit change procedure have now been replaced by resources 32, 34, 42 for the destination units 35, 45 in order. Thus, as can be appreciated from Figure 6D, the unit change procedure of the present invention can be terminated in the following situation: User terminal 10 has radio transmission resources 32, 34, 42 configured by different base stations 30, 40. If the mobile user terminal 10 continues to move (e.g., further into the third unit 45), the two radio transmission resources 32 disposed in the second unit 35 will be replaced in sequence by the radio resources in the third unit 45 in accordance with the present invention. 34.

Similar to the above-described principle that the unit change procedure of the present invention can end with the case where the user terminal has radio transmission resources configured in different units, it can be started from the case where the user terminal has resources configured by different base stations. The unit changes will be further described herein with reference to Figures 8A through 8D.

In the previous example of the unit change procedure of the present invention, a single radio transmission resource has been replaced in sequence. However, the invention is not limited thereto. This means that in at least one of the multi-step (sequential) resource replacement of the present invention, one of the at least two resources can be replaced by other resources. This is schematically illustrated by Figures 7A through 7D.

Figure 7A illustrates two cells 25, 35 and two base stations 20, 30 of a cellular communication system 1. A mobile user terminal 10 is present in the first unit 25 and has (in this example) configured with four radio transmission resources 22, 24, 26, 28 to communicate with the base station 20 of the unit 25. The user terminal 10 is removed from the current serving base station 20 and moved into the radio coverage area 35 of the second base station 30. In the first step of replacing the sequential resources by the unit change of the present invention, the initially configured resources 22, 24, 26, 28 are replaced by a plurality of resources 32, 34 configured by the second base station 30 for the terminal 10. One of a plurality (two) of resources 22, 24, see Figure 7B. In this example, in the unit change procedure, the user terminal 10 thus has two resources 26, 28 configured to communicate with the old base station 20 and two resources 32, 34 configured to communicate with the new base station 30.

By replacing the resource 26 in the unit 25 with a resource 36 in the destination unit 35 first, the sequential replacement of the remaining two resources 26, 28 is performed non-limitingly in two steps, see Figure 7C. In Figure 7D, the last resource 28 is replaced by a new resource 38 in the second unit 35. Those skilled in the art will appreciate that the final two radio transmission resources 26, 28 can of course be replaced by a group and replaced with resources 22, 24 in one step. The particular manner in which the resources are replaced in order may be based, at least in part, on the different substitution criteria described further below to perform the unit changes of the present invention in the most appropriate manner depending on the present situation.

Figure 8A illustrates three cells 25, 35, 45 and three base stations 20, 30, 40 of a cellular communication system 1. A mobile user terminal 10 is present in an overlapping area of the first unit 25 and the second unit 35 and has configured the first radio transmission resource 24 in this example to communicate with the base station 20 of the first unit 25 and The second resource 32 communicates with the base station 30 of the second unit 35. The situation illustrated in Figure 8A can be generated from the results of a previously executed phase handover procedure in accordance with the present invention.

In a clear contrast to prior art soft handoff, in a particular embodiment of the invention illustrated in Figure 8A, the original data transmitted on the first resource 24 is different from the original data transmitted on the second resource 32. Therefore, the bit stream that is to be scrambled, modulated, etc. by the first base station 20 (or the user terminal 10) and transmitted on the first resource 24 is different from the second resource 32 to be used and by the second The base station 30 (or the user terminal 10) mutes, modulates, etc., and then transmits the bit stream. Therefore, in this particular embodiment, the duplicate source material is typically not transmitted on the two resources 24,32. However, if, for example, the user terminal has configured at least two resources in the same first unit and possibly resources other than the data in the different units, the first unit may also be used. At least two resources send duplicate information. Moreover, the present invention contemplates that sometimes copy information may actually be transmitted on two resources 24, 32, but this typically occurs over time and during a limited time period.

In FIG. 8B, the user terminal has moved toward the third base station 40, thereby providing communication service in the third unit 45. Therefore, in the first step of replacing in order, the resources arranged in the second unit 35 are replaced by resources 42 assigned to the user terminal 10 in the third unit 45. However, the user terminal 10 then moves back from the third base station 40 in Fig. 8C. This means that in the second replacement step, resources 32 are used in place of the resources allocated to the user 10 in FIG. 8C for communication with the second base station 30 in the second unit 35. It should be noted that in these two steps, the resources configured to communicate with the first base station 20 are not affected. In FIG. 8D, the user terminal 10 continues to move toward the second base station 30 and employs the second resource 34 configured to communicate with the second unit 35 in place of the resources disposed in the first unit 25 in a third replacement step.

It will be apparent from the above description that the sequential data replacement of the present invention may thus involve more, less or equal amounts of resources originally allocated to the user terminal based on the particular movement of the mobile user terminal between the different units. Replace the steps.

This means that the unit changes of the invention disclosed in Figures 4A to 8D and the above description are very flexible in terms of the base station and communication unit in which the program starts, during the actual unit change, and in which the user terminal ends. . In addition, there is greater flexibility in how to manage multiple resources during sequential replacement, which means that the number of resources replaced in each step can be adapted to a particular situation and what base stations are involved in this replacement to reach the macro Advantageous effects in terms of diversity, service coverage, and stability.

In a preferred but non-limiting embodiment of the invention, the resources that replace the originally configured resources in order are preferably the same type of resources. Thus, if the unit change procedure begins with, for example, four downlink resources configured for the user terminal, once the unit change is completed, the user terminal still has configuration configured to communicate only in at least one other unit. Four downlink resources.

If the user terminal has been configured with two uplink resources and two downlink resources in the current service unit, the two resource types can be manipulated jointly or separately. For example, by arranging two downlink resources to a terminal in at least one other unit, the downlink resources can be individually replaced in the sequential resource replacement in accordance with the present invention. Thus, individual sequential replacement of uplink resources can then be performed in parallel or some time period before or after the downlink resource is replaced. If all resources are managed together, one or more downlink (uplink) resources may be replaced in the first step and one or more uplink (downlink) resources are replaced in the second sequential step.

FIG. 9 is a flow chart illustrating a specific embodiment of the sequential resource replacement step S3 of FIG. This flowchart basically illustrates an algorithm that is substituted in order to perform the present invention. The method continues from step S2 in Figure 3. In the next step S10, a resource counter (TOTAL) is set as the total number of resources (N) in place of the unit change procedure. Accordingly, the replacement counter (REPLACED) representing the total number of replaced resources is set to zero because the resources have not been replaced. The one-step counter (k) is set to zero and represents the total number of sequential resource replacement steps that have been performed.

In the next step S11, M ₀ radio transmission resources are replaced by resources allocated to user terminals in at least one external or different unit. The number of M _{0 of the} replaced resource is equal to or greater than one but less than the total number of configured resources, ie 1 M ₀ <N. M ₀ M ₀ resources such resources available for the external unit can be substituted or using external unit may be used for different resources in total M ₀ substituents.

In the next step S12, the step counter k is incremented by one to indicate that the first step of the multiple step resource replacement has been completed. The replaced counter REPLACED accordingly increases the number M ₀ of resources replaced in this step. The next step S13 investigates whether the step counter k is greater than one, that is, whether at least two resource replacement steps have been performed. If this is not the case, the method returns to step S11, where M ₁ radio resources are now replaced. This/the M ₁ radio resources may be replaced by radio transmission resources in units that are in phase or different from the resources replacing the first M ₀ resources. Step S12 increases the step counter k to 2 and now sets the REPLACED counter to M ₀ + M ₁ .

In this case, the criterion in step S13 is implemented because the counter k is currently two, which is greater than one. The method thus proceeds to step S14 where it is investigated whether the replaced counter is equal to the total number of resources for the user terminal, ie whether REPLACED=TOTAL. If this is not the case, all previous radio transmission resources of the user terminal have been replaced and the unit change has been completed. If the number of replaced resources has not reached the total number of resources initially allocated to the user terminal, then the method continues to step S11 and a new resource replacement step is performed.

Preferably, the manner in which the number M _k of resources to be replaced in the step counter k is determined, for example, is predefined according to different substitution criteria. It can also include a threshold check so that it does not replace more resources than the total number of resources originally configured, ie to prevent REPLACED= More than TOTAL. However, it should be noted that phase handover can be performed in a number of replacement steps than the amount of data originally configured for the user terminal. This is because the user terminal can move back and forth between different units, which requires resource replacement.

Figure 10 is a flow diagram of additional steps of the unit change method illustrated in Figure 3. The method continues from step S2 in Figure 3. In the next step S20, at least one substitution criterion is provided. This substitution criterion is used by the unit that triggers the unit change procedure (user terminal, base station or control node) or by another unit (usually a control node) that is managed or involved in the decision In fact, how to execute the unit change program. As explained in the above text, the unit change of the present invention provides the flexibility to decide which resources will be replaced in each step, when such replacement will occur, and what new resources are to be allocated to the user terminal.

An example of a replacement criterion that can be provided and used in accordance with the present invention is one of the values of a timer associated with a unit change. This timer can be configured in the user terminal, one of the base stations involved or the control network node. Each step of resource replacement can be performed, for example, after a predefined period of time after detecting a need for a unit change. Alternatively, a minimum/maximum time period can be utilized between the two substitution steps in the unit change procedure. A timer can therefore be used to match the timing of the unit changing sub-steps.

In another example, a quality parameter can be used that represents the radio quality of the communication link between the mobile user terminal and the original base station. For example, it may be more advantageous to replace more resources in the first substitution step under conditions in which the radio quality is rapidly degraded as compared to the case where the link quality is degraded more slowly. In the first case, new resources in at least one destination unit must be quickly configured, since old resources may become unusable for the user terminal due to rapid degradation of quality. In order to provide maximum output, it is often advantageous to replace a subset of multiple resources as compared to replacing only a single resource in the first step.

Accordingly, a radio quality metric can be used as a replacement criterion that represents the radio quality of the mobile subscriber terminal in at least one destination unit that is moved in. If the quality (eg, received signal strength) increases slowly, the unit change procedure can advantageously be extended over time, for example by using more than two substitution steps (where applicable) and/or adding two substitution steps. The time period between executions.

The buffer level in the transmit buffer configured in the user terminal and including the data for the current serving base station can also be used as a replacement criterion in accordance with one of the present inventions. If the user terminal has a large amount of data to transmit to the base station shortly before the start unit change, it is generally advantageous to keep as much uplink transmission resources as possible configured for the base station until the user terminal is emptied. This information in the buffer. This means that in the first step or in a few steps, instead of a single uplink resource, instead of replacing multiple resources in the first (minor) step.

In a similar manner, the buffer level in the current serving base station can be related to the unit change operation. For example, if the base station has a large amount of data in the transmit buffer and the data is for the user terminal, the downlink resources can be replaced in multiple steps to maintain as much resources as possible to the base station until This material has been disseminated to the user terminal. This representation typically replaces a single resource in the first few steps and can then replace any remaining resources in a single step.

The buffer level in the destination base station and/or the control network node connected to the old and new base stations may also be associated with the execution unit change procedure.

Therefore, at least one of the substitution criteria is preferably used when deciding when and how to change the execution unit. This decision can be made by the user terminal, one of the base stations involved, or the control network node. In the latter case, the control node can inform the parties involved in the unit change of the provided replacement criteria or how to perform the unit change.

There may be a preset scheme that defines how to perform a unit change. The unit change can be made according to this preset scheme, that is, how many multiple replacement steps, how many uplink resources are to be replaced in each step, how much downlink resources to replace in each step, when to perform the replacement step, and the like. If it is preferred to expand from the preset scheme, it is preferable to generate a control message (for example, a unit changed by the control node or the trigger unit), which includes information specifying how to perform the unit change. The substitution criteria provided are preferably used to generate such control messages.

In an alternate embodiment, all units take different predefined unit change schemes and decide on a particular scheme to utilize in a given unit based on at least one replacement criterion.

The invention thus provides several possibilities for adapting the unit change procedure for current conditions and thus provides a very flexible and versatile handover. The method then proceeds to step S3 where the radio resources are replaced in sequence according to the selected scheme or according to the provided replacement criteria.

Figure 11 is a flow chart showing a unit change control method in accordance with the present invention. The control method is applicable to a cellular radio communication system comprising an active user terminal present in the first unit and having a plurality of radio transmission resources simultaneously configured to communicate with the first base station associated with the first unit . In a first optional step S30, the need for a unit change is detected. This step basically corresponds to step S2 in Fig. 3 and will not be further explained. In the next step S31, a unit change control message is generated. The control message command replaces the plurality of radio resources in sequence with radio transmission resources configured to the mobile terminal to communicate with the at least one base station. The resulting control message is assigned to interested parties, such as the user terminal, the first base station, and the new service base station. This control method can be performed by providing an application in a user terminal, one of the communication base stations, or a control network node (such as a BSC or Radio Network Controller (RNC)). The method then ends.

When the parties receive the control message, the unit change is performed by replacing the radio transmission resources in order (i.e., according to step S3 of FIG. 3).

It has been stated in the above text that the phase handover of the present invention generally precedes the exchange of information between the originating and network nodes (e.g., base stations and control network nodes) and the mobile user terminals involved. This information is sent to the data and results relating to quality measurements performed throughout the communication system and used in step S30 of Figure 11, as a basis for deciding whether a phase handover should be initiated. In addition, the signaling system typically occurs during phase handover and is used to inform the relevant unit of changes in the implementation of phase handover.

For example, once phase transfer is initiated, the program can continue in a convincing manner in different ways. In a first embodiment, each "segment" of phase handover involving a subset of radio transmission resources configured for a logical data stream can be individually evaluated and signaled. The uplink and downlink resources can be manipulated separately or together. While this requires additional signaling, it provides maximum flexibility because each segment can be performed in the dominant radio environment at the most appropriate time for the ongoing service.

In an alternate embodiment, the signaling will only occur when the phase handover procedure is initiated, and then each segment will be performed based on resource replacement criteria that are propagated in the initial signaling phase or pre-defined according to a standard.

Therefore, a more extended or less extended transmission may be based on the initial allocation of the command message in step S32 of FIG.

The present invention can be advantageously applied to other techniques to improve a unit change or handover procedure. An example of such a technique that increases the stability of handover is illustrated in PCT/SE2005/000365 and is indicated as unit muting. Cell muting improves handover stability by temporarily enhancing the radio environment of the user terminals that are handed over in the delivery. This is achieved by muting one or more primary interfering units during all or all of the handover procedures or only when certain conditions are met, such as the first handover command not arriving. Or, according to certain criteria, the user is considered to be in a sufficiently poor radio condition.

As stated in the above text, the mobile user terminal regularly measures the received signal strength on the frequency used by the neighboring base station based on the list of neighboring cells it receives from the network. During idle time slots, in the case of the GSM system, the terminal also attempts to identify neighboring base stations by decoding its base station identification code (BSIC). The correctly decoded BSIC and received signal strength measurements are needed so that the measurements can be used for handover decisions. Once the measurements are received by the network, the measurements are filtered and the handover criteria are evaluated in a network node (typically a BSC). Such handover criteria may include signal strength hysteresis values to minimize ping-pong handover and other signal strength or timing penalty triggered by previous channel management operations.

The procedure for neighbor cell measurement, identification, reporting, filtering, and handover criteria evaluation is performed before any handover commands can be transmitted. It is usually implemented in fast-moving users and uneven radio environments in an irregular unit plan. For these reasons, the handover command is typically transmitted to the mobile user terminal when the mobile user terminal is already in the nominal coverage area of the target base station and is further removed from the service base station. In the case of strict reuse of radio resources, the handover procedure must be clearly enforceable under poor radio conditions in order to prevent the call from being stopped.

For example, the characteristics of the radio environment experienced by the mobile user may be a carrier to interference ratio (C/I), which may be illustrated for the downlink, from the first serving base station in the first unit, and the interference Starting from a number of surrounding base stations containing the target base stations in the second unit.

Based on the above reasoning, the handover command is usually transmitted to the mobile user terminal when the mobile user terminal is already in the second unit. At this point, the base station in the second unit is likely to be the main source of downlink interference. In a specific embodiment of unit muting, each frequency in the case of a suitable frequency or frequency hop and the transmission on the time slot of the base station in the second unit transmits a handover command from the first unit to the mobile user terminal. The machine is simply muted, increasing the chance of C/I and correctly receiving delivery commands. In an alternate embodiment, this approach can be used to silence the appropriate transmissions from several interfering base stations.

Because of the cost involved in temporarily muting the launch, a more attractive embodiment may be that only the lost burst or frame for the user in the silent unit, and the control signaling in achieving muting, Silent emissions in the case of certain criteria. One possibility would be to consider measurement reports for the radio link to the service unit, such as received signal strength (eg RXLEV in GSZM) and/or quality of reception (eg bit error represented by RXQUAL in GSM) Rate measurement report, and apply interference muting only if the link quality to the serving base station is below a predefined threshold. Another possibility would be to mute only if the initial handover attempt failed. As the terminal continues to move away from the service base station, subsequent attempts are likely to occur under more difficult radio conditions, making muting a more attractive option. It is of course possible to use a combination of these and other criteria required to silence the triggering unit. Knowledge of the location and/or speed of the action will be used as an alternative to the specific embodiment.

If this unit muting solution is applied as a supplement to the present invention, then more handovers can be successful earlier, resulting in reduced interference and fewer stop calls. In addition, because the frame may be stolen each time it is delivered in any situation (such as in GSM), more stable handoffs using cell muting are likely to reduce lost frames in such networks. The total number. In many cases where frequency hopping or similar techniques are employed, lost bursts can be managed in any way using channel codes and there is no negative quality impact at all. It should also be noted that cell muting makes the handover procedure more stable without unintended interference in the network, which is in accordance with the present invention.

Figure 12 is a schematic block diagram of a unit change manager 100 in accordance with the present invention. This manager 100 typically includes an input and output (I/O) unit 110 for communicating with external units. The I/O unit 110 can be configured to receive quality-related measurements that are used to determine whether to trigger a unit change in accordance with the present invention. These measurements can be performed by different units involved in the unit change and other units in the communication system.

In an alternate embodiment, particularly when the unit change manager 100 is implemented in a communication base station or mobile user terminal, the radio link analyzer 120 can be provided in the manager 100 to perform an analysis of the current radio situation. . In a particular embodiment, the analyzer 120 can estimate the received signal strength using the I/O unit 110 and generate a link quality metric or estimate based on the received signal strength. Other quality related parameters can also be analyzed and provided by the radio link analyzer 120.

A unit change detector 130 is configured in the unit change manager 100 to detect the need for unit changes involving a user terminal. The detector 130 preferably uses input information from the I/O unit 110 and/or the radio link analyzer 120 when performing the detection. This means that the detection is based on radio quality parameters such as received signal strength and/or estimated unit load. If a need for a unit change is detected, the detector 130 signals the radio resource replacer 140 in the unit manager 100 to command a unit change to be initiated.

The resource replacer 140 is configured in the unit change manager 100 to employ a radio transmission resource configured to be communicated to a terminal to communicate with at least one base station having a unit different from a first unit, and sequentially configured to The mobile user terminal communicates with a plurality of communication resources of the first base station of the first unit.

In an alternate embodiment, the resource replacer 140 is configured to replace at least one of the first and second radio transmission resources simultaneously configured for communication to a user terminal in the first and second units, respectively. . Furthermore, the original data transmitted on the at least first resource is different from the original data transmitted on the at least second resource. The replacer 140 then replaces the at least first and second resources in sequence (i.e., in at least two steps) with radio transmission resources configured to the user terminal to communicate with the at least one base station.

This means that the replacement 140 replaces a plurality of communication resources in at least two steps. It should be noted that the substitute 140 may replace multiple uplink resources, may replace multiple downlink resources or may replace multiple uplink and downlink resources. The new at least one service unit involved in this unit change may be the same base station as the first (old) service base station in the case of intra-site handover, or one or more other in the case of so-called inter-site handover Base station.

The resource replacer 140 may perform this sequential resource replacement in accordance with a predetermined replacement scheme that specifies at least one of: i) how many steps should be included in order, ii) how much resources should be replaced in different steps, iii) What resources will be replaced in different steps, and iv) when to perform those steps. This preset scheme is generally applicable and applicable to most unit change procedures and can be determined as an averaging scheme (e.g., based on information changed from a plurality of different units previously executed by the unit manager 100), or as specified by a standard. The unit change manager 100 can have a program memory 150 for storing information of the preset scheme or can provide related information from an external unit.

In an alternate embodiment, the wireless resource replacer 140 takes a number of different predefined replacement schemes, such as those provided in the scheme memory or repository 150. The replacer 140 then selects the most appropriate replacement scheme to use for the current unit change procedure based on the input information. The input information may comprise at least one of: i) a value of one of the timers associated with a unit change, ii) a quality parameter representative of the radio quality of the communication link between the user terminal and the old service unit, iii a quality parameter representative of the radio quality in the possible candidate destination units, iv) a transmission buffer configured in the user terminal, the old serving base station, the candidate base station for the new serving base station, or a control network node One of the buffer levels, or v) a series of one or more of the above qualities i) to iv).

Information about what alternatives to utilize may also be received from an external node (e.g., a control network node).

The unit manager 100 can of course also operate without any available predefined replacement schemes and can then instead negotiate how other external party execution unit changes should be used or received from a control network node regarding a suitable unit change procedure. Information.

The units 110 to 140 of the unit change manager 100 may be provided as software, hardware, or a combination thereof. Units 110 through 150 may be implemented together in a user terminal, a base station, a control node, or another network node. In addition, a distributed implementation can be used to provide certain units in different network nodes.

Figure 13 is a schematic block diagram of a unit change controller 200 in accordance with the present invention. This controller 200 typically includes an I/O unit 210 for communicating with external units. The I/O unit 210 is specifically configured to transmit a control message that commands the replacement of multiple radio transmission resources in accordance with the present invention in sequence. The unit change controller 200 also includes an optional radio link analyzer 220, a change detector 230 and an alternative repository 250. The operations and functions of the units 220, 230, and 250 are similar to the corresponding units in the unit change manager disclosed in FIG. 12 and described above.

Controller 200 also includes a control message engine 240. The message engine 240 preferably responds to the unit change detection signal of the self-change detector 230 to cause the message engine 240 to provide or generate a control message. The designated receiver of the control message command message is configured to be assigned to the terminal device in order to replace the radio transmission resources communicated with the terminal device with at least one base station having a unit different from a first unit. The first base station of the first unit communicates with a plurality of radio transmission resources.

In an alternative embodiment, one of the control message command messages specifies that the receiver uses the radio transmission resources configured to communicate with the at least one base station in sequence to be simultaneously configured for the mobile user terminal to be at least two. Multiple radio transmission resources for communication in different units.

Message engine 240 may use information from different predefined replacement schemes available from solution repository 250 in the process of generating control messages.

The control message is then provided to I/O unit 210, which forwards the message to the user terminal, the current serving base station, at least one possible new service base station, and/or any other node involved in the unit change procedure.

The units 210 to 240 of the unit change controller 200 may be provided as software, hardware, or a combination thereof. Units 210 through 250 may be implemented together in a user terminal, a base station, a control node, or another network node. In addition, a distributed implementation can be used to provide certain units in different network nodes.

A person skilled in the art will recognize that various modifications and changes can be made to the invention without departing from the scope of the invention as defined by the appended claims.

1. . . Communication Systems

10. . . Mobile user terminal

20. . . First base station

twenty two. . . Radio resources

twenty four. . . Radio resources

25. . . The first unit

26. . . Radio resources

28. . . Radio resources

30. . . Second base station

32. . . Radio resources

34. . . Radio resources

35. . . Second unit

36. . . Radio resources

38. . . Radio resources

40. . . Base station

42. . . Radio resources

45. . . Third unit

90. . . Control network node

100. . . Unit change manager

110. . . I/O unit

120. . . Radio link analyzer

130. . . Change detector

140. . . Radio resource replacer

150. . . Program repository

200. . . Unit change controller

210. . . I/O unit

220. . . Radio link analyzer

230. . . Change detector

240. . . Control message engine

250. . . Program repository

The invention and its additional objects and advantages are best understood by reference to the above description taken in conjunction with the accompanying drawings in which: Figures 1A to 1C are diagrams illustrating a hard handover procedure in accordance with the prior art. 2A to 2C are diagrams illustrating a soft handover procedure according to the prior art; FIG. 3 is a flow chart illustrating a unit change method according to an embodiment of the present invention; FIGS. 4A to 4C are diagrams illustrating the present invention A diagram of a unit change procedure performed in a cellular radio communication system of one embodiment; FIGS. 5A through 5C are diagrams illustrating a unit change procedure performed in a cellular radio communication system in accordance with another embodiment of the present invention. Figures 6A through 6D are diagrams illustrating a unit change procedure performed in a cellular radio communication system in accordance with another embodiment of the present invention; and Figures 7A through 7D are diagrams illustrating a honeycomb in accordance with another embodiment of the present invention; A diagram of a unit change procedure performed in a radio communication system; FIGS. 8A through 8D are diagrams illustrating a unit change procedure performed in a cellular radio communication system in accordance with another embodiment of the present invention. FIG. 9 is a flow chart illustrating the sequential replacement steps of FIG. 3 in more detail in accordance with an embodiment of the present invention; FIG. 10 is a flow chart illustrating additional steps of the unit changing method of FIG. 3; A flowchart of a unit change control method according to an embodiment of the present invention; FIG. 12 is a schematic block diagram of a unit change manager according to an embodiment of the present invention; and FIG. 13 is a specific embodiment of the present invention. The unit changes the schematic block diagram of the controller.

Claims (31)

A unit change method in a cellular radio communication system, the system comprising a mobile user terminal present in a first unit and having a first base station simultaneously configured to communicate with the first unit a plurality of radio transmission resources, the method comprising: replacing the plurality of radio transmission resources configured to the mobile user terminal to communicate with at least one base station having a unit different from the one of the first units Radio transmitting resources, such that the plurality of radio transmission resources are not simultaneously replaced, wherein the sequential replacement is performed in at least two steps, in which a first number of the plurality of radio transmission resources are Instead, the remaining number of the plurality of radio transmission resources is replaced in a subsequent step of one or more time divisions. The method of claim 1, wherein the sequentially replacing step comprises replacing the plurality of radio transmission resources configured to the mobile user terminal to communicate with a second base station having an associated second unit in sequence Radio transmission resources. The method of claim 1, wherein the sequentially replacing step comprises employing a configuration to the mobile user terminal to when the mobile user terminal system appears in a second unit associated with the first base station The radio transmission resources of the first base station communication replace the plurality of radio transmission resources in sequence. The method of claim 1, wherein the sequentially replacing step comprises using a radio configured to communicate with the mobile user terminal to communicate with a plurality of base stations The transmit resources replace the plurality of radio transmit resources in sequence, wherein each of the plurality of base stations has an associated individual unit and at least one of the individual units is different from the first unit. The method of claim 1, the method comprising detecting a demand for a unit change based on at least one of an estimated radio quality metric and an estimated unit load metric, and performing the sequential replacement step to respond to the detection. The method of claim 1, wherein the mobile user terminal has N radio transmission resources configured to communicate with the first base station, wherein N is an integer equal to or greater than two, and the sequential replacement step includes The following steps: replacing M radio transmission resources of the N radio transmission resources by M radio transmission resources configured to the mobile user terminal to communicate with the at least one base station, wherein M<N; propagating data on the M radio transmission resources and propagating data on the NM remaining radio transmission resources; and employing NM transmission resources configured to communicate with the mobile user terminal to communicate with the at least one base station Replace these NM remaining radio transmission resources. The method of claim 6, wherein the data transmitted between the mobile user terminal and the at least one base station is used by the M radio transmission resources and the NM radio transmission resources are used at the mobile user terminal The data communicated with the first base station is associated with an entity, data link, network, transport, session, presentation or application layer. The method of claim 6, wherein the data transmitted between the mobile user terminal and the at least one base station is used by the M radio transmission resources and the NM radio transmission resources are used at the mobile user terminal The information transmitted between the first base station is based on common information. The method of claim 6, wherein the user plane information that is transmitted between the mobile user terminal and the at least one base station using the M radio transmission resources is not in use with the NM radio transmission resources in the action The user terminal is associated with user plane data that is transmitted between the first base station. The method of claim 6, wherein the control data transmitted between the mobile user terminal and the at least one base station using the M radio transmission resources is used by the mobile user using the NM radio transmission resources The terminal is associated with control information transmitted between the first base station. A unit change method in a cellular radio communication system, the system comprising a mobile user terminal and having at least a first radio transmission resource configured and configured to communicate with a base station associated with the same first unit and configured to At least one second radio transmission resource associated with a base station associated with a second unit, the method comprising: replacing the at least the radio transmission resource configured to the mobile user terminal with the at least one base station in sequence The first radio transmission resource and the at least second radio transmission resource, so that the plurality of radio transmission resources are not simultaneously replaced, wherein the sequential replacement is performed in at least two steps, and the first step is first The number of these multiple radio transmission resources is replaced, And in a subsequent step of one or more time divisions, the remaining number of the plurality of radio transmission resources is replaced, wherein the original data to be transmitted using the at least first radio transmission resource is different from the at least second to be used The original data sent by the radio transmission resource. A unit change control method in a cellular radio communication system, the system comprising a mobile user terminal appearing in a first unit and having a first base station simultaneously configured to be associated with the first unit Transmitting a plurality of radio transmission resources, the method comprising: replacing, by order, a radio transmission resource generation command configured to the mobile user terminal to communicate with at least one base station having a unit different from the one of the first units One of the plurality of radio transmission resources changes the control message so that the plurality of radio transmission resources are not simultaneously replaced, wherein the sequential replacement is performed in at least two steps, in the first step A plurality of the plurality of radio transmission resources are replaced, and in a subsequent step of one or more time divisions, the remaining number of the plurality of radio transmission resources are replaced. The method of claim 12, wherein the mobile user terminal has N radio transmission resources configured to communicate with the first base station, wherein N is an integer equal to or greater than two, and the sequential replacement comprises: Replacing M radio transmission resources of the N radio transmission resources with M radio transmission resources configured to communicate with the mobile user terminal to communicate with the at least one base station, wherein M<N; propagating data on the M radio transmission resources and propagating data on the NM remaining radio transmission resources; and employing NM transmission resources configured to communicate with the mobile user terminal to communicate with the at least one base station Replacing the NM remaining radio transmission resources, wherein the user plane information used between the mobile user terminal and the at least one base station using the M radio transmission resources is not related to the use of the NM radio transmission resources Corresponding to user plane data transmitted between the mobile user terminal and the first base station. The method of claim 13, wherein the control data transmitted between the mobile user terminal and the at least one base station using the M radio transmission resources is used by the mobile user using the NM radio transmission resources The terminal is associated with control information transmitted between the first base station. A unit change control method in a cellular radio communication system, the system comprising a mobile user terminal and having at least a first radio transmission resource and configuration configured to communicate with a base station associated with the same first unit At least one second radio transmission resource in communication with a base station associated with the same second unit, the method comprising: generating a command in sequence using a radio transmission resource configured to communicate with the mobile user terminal to communicate with the at least one base station Replacing the at least first radio transmission resource and the at least one second radio transmission resource unit change control message, so that the plurality of radio transmission resources are not the same Substituting, wherein the sequential replacement is performed in at least two steps, in which a first number of the plurality of radio transmission resources are replaced, and in a subsequent step of one or more time divisions And remaining digits of the plurality of radio transmission resources are replaced, wherein the original data to be transmitted using the at least first radio transmission resource is different from the original data to be transmitted using the at least second radio transmission resource. A unit change manager comprising a radio transmission resource configured to communicate with a mobile user terminal configured to communicate with at least one base station having a unit different from the first unit, in order Simultaneously configuring hardware for the mobile user terminal to communicate with a plurality of radio transmission resources of a first base station of a first unit, so that the plurality of radio transmission resources are not simultaneously replaced, wherein the order is The substitution system will be performed in at least two steps, in which a first number of the plurality of radio transmission resources are replaced, and in a subsequent step of one or more time divisions, the plurality of radio transmissions The remaining number of resources is replaced. A manager of claim 16, wherein the hardware is configured to replace the radio transmission resources configured to the mobile user terminal to communicate with a second base station having an associated second unit in sequence Multiple radio transmission resources. The manager of claim 16, wherein the hardware is configured to be configured for the mobile user terminal to appear at the mobile user terminal system The plurality of radio transmission resources are replaced in sequence by the radio transmission resources in communication with the first base station in one of the second units associated with the first base station. A manager of claim 16, wherein the hardware is configured to replace the plurality of radio transmission resources in sequence with radio transmission resources configured to communicate with the plurality of base stations to the mobile user terminal, wherein Each of the plurality of base stations has an associated individual unit and at least one of the individual units is different from the first unit. The manager of claim 16, further comprising a detector for detecting a demand for the unit change based on at least one of an estimated radio quality metric and an estimated unit load metric, and A detection signal is generated based on the detection, and the hardware is configured to perform the sequential replacement of the plurality of radio transmission resources to respond to the detection signal. The manager of claim 16, wherein the mobile user terminal has N radio transmission resources configured to communicate with the first base station, wherein N is an integer equal to or greater than two, and the replacement includes Replacing M radio transmission resources of the N radio transmission resources with M radio transmission resources configured to communicate with the mobile user terminal to communicate with the at least one base station, wherein M<N; propagating data on the M radio transmission resources and propagating data on the NM remaining radio transmission resources; and employing NM transmission resources configured to communicate with the mobile user terminal to communicate with the at least one base station Replacing the NM remaining radio transmission resources, wherein the user plane information used between the mobile user terminal and the at least one base station using the M radio transmission resources is not related to the use of the NM radio transmission resources Corresponding to user plane data transmitted between the mobile user terminal and the first base station. The manager of claim 21, wherein the control data transmitted between the mobile user terminal and the at least one base station using the M radio transmission resources is used in the action using the NM radio transmission resources The terminal device is associated with control information transmitted between the first base station. A unit change manager, comprising: a radio transmission resource configured to communicate with a mobile user terminal to communicate with at least one base station, in order to replace the configuration with the mobile user terminal with a first At least one first radio transmission resource of the first base station communication of the unit and hardware for simultaneously configuring the mobile user terminal to communicate with at least one second radio transmission resource of the base station of the second unit, Having the plurality of radio transmission resources not being simultaneously replaced, wherein the sequential replacement is configured to be performed in at least two steps, in which a first number of the plurality of radio transmission resources are replaced And in a subsequent step of one or more time divisions, the remaining number of the plurality of radio transmission resources are replaced, and wherein the original data to be transmitted using the at least first radio transmission resource is different from the At least a second radio transmission resource The original data sent. A network node that includes a unit change manager, such as request item 16. A mobile user terminal that includes a unit change manager, such as request item 16. A unit change controller comprising: hardware configured to generate a unit change control message, the message command being configured to a mobile user terminal to be associated with a unit having a different unit than the first unit The plurality of radio transmission resources of the at least one base station communication are sequentially replaced with a plurality of radio transmission resources that are simultaneously allocated to the mobile user terminal to communicate with the first base station of one of the first units to enable the plurality of radio transmission resources Not being replaced at the same time, wherein the sequential replacement is performed in at least two steps, in which a first number of the plurality of radio transmission resources are replaced, and the subsequent steps separated by one or more times The remaining number of the plurality of radio transmission resources are replaced, and a transmitter for transmitting the unit change control message to the user terminal, the first base station, and the at least one base station One. The unit change controller as in claim 26, wherein the mobile user terminal has N radio transmission resources configured to communicate with the first base station, wherein N is an integer equal to or greater than two, and the order Substituting includes replacing M radio transmission resources of the N radio transmission resources with M radio transmission resources configured to the mobile user terminal to communicate with the at least one base station, wherein M<N; propagating data on the M radio transmission resources and propagating data on the NM remaining radio transmission resources; and employing NM transmission resources configured to communicate with the mobile user terminal to communicate with the at least one base station Replacing the NM remaining radio transmission resources, wherein the user plane information used between the mobile user terminal and the at least one base station using the M radio transmission resources is not related to the use of the NM radio transmission resources Corresponding to user plane data transmitted between the mobile user terminal and the first base station. The unit change controller as claimed in claim 27, wherein the control data transmitted between the mobile user terminal and the at least one base station using the M radio transmission resources is used by the NM radio transmission resources The mobile user terminal is associated with control information transmitted between the first base station. A unit change controller, characterized by: generating means for generating a unit change control message, the message commanding a radio transmission resource configured to communicate with at least one base station in order to replace the configuration Giving the mobile user terminal terminal at least one first radio transmission resource in communication with the first base station of a first unit and simultaneously configuring the mobile user terminal to communicate with one of the base stations of a second unit At least one second radio transmission resource, wherein the at least first radio transmission resource is to be used for transmission The original data sent is different from the original data to be transmitted using the at least second radio transmission resource, so that the plurality of radio transmission resources are not simultaneously replaced, wherein the sequential replacement is performed in at least two steps, a first number of the plurality of radio transmission resources in the first step are replaced, and in a subsequent step of one or more time divisions, the remaining number of the plurality of radio transmission resources are replaced, wherein The original data transmitted by the at least first radio transmission resource is different from the original data to be transmitted using the at least second radio transmission resource, and a transmitter for transmitting the unit change control message to the user terminal At least one of the base station and the at least one base station. A network node that includes a unit change controller as in request item 26. An mobile user terminal includes a unit change controller as in request item 26.