Radio resource control

Field

The invention relates to a radio resource control method, a mobile terminal and a computer program implementing the radio resource control method.

Background

A mobile terminal may have a multi-access capability enabling the mobile terminal to be connected to a plurality of radio access networks which utilize different radio access technologies. The service areas of such radio ac- cess networks may overlap one another, and there are several alternative radio access networks for the mobile terminal to choose from. Therefore, it is useful to consider criteria on the basis of which radio resources in a multiaccess mobile terminal case are controlled.

Brief description of the invention An object of the invention is to provide an improved mobile terminal, method and computer program. According to a first aspect of the invention, there is provided the mobile terminal capable of connecting to a plurality of radio access networks which apply different radio access technologies, the mobile terminal comprising: a network analyzer configured to determine data transfer characteristics between the mobile terminal and a target node in a plurality of radio access networks; and a selecting unit configured to select a radio access network for application data transfer between the mobile terminal and the target node on the basis of a comparison between the data transfer characteristics and data transfer requirements of at least one mobile terminal appli- cation communicating with the target node.

According to a second aspect of the invention, there is provided a method of controlling radio resources, the method being carried out in a mobile terminal capable of connecting to a plurality of radio access networks which apply different radio access technologies, the method comprising: determining data transfer characteristics between the mobile terminal and a target node in a plurality of radio access networks; and selecting a radio access network for application data transfer between the mobile terminal and the target node on the basis of a comparison between the data transfer characteristics and data

transfer requirements of at least one mobile terminal application communicating with the target node.

According to another aspect of the invention, there is provided a computer program encoding a computer program of instructions for executing a computer process in a mobile terminal, wherein the mobile terminal is capable of connecting to a plurality of radio access networks which apply different radio access technologies, the computer process comprising: determining data transfer characteristics between the mobile terminal and a target node in a plurality of radio access networks; and selecting a radio access network for appli- cation data transfer between the mobile terminal and a target node on the basis of a comparison between the data transfer characteristics and data transfer requirements of at least one mobile terminal application communicating with the target node.

List of drawings In the following, the invention will be described in greater detail with reference to the embodiments and the accompanying drawings, in which

Figure 1 shows an example of the structure of a communication system;

Figure 2 shows a first example of the structure of a mobile terminal; Figure 3 shows a second example of the structure of a mobile terminal;

Figure 4 shows an example of a network analyzer according to an embodiment of the invention;

Figure 5 shows an example of a network selector according to an embodiment of the invention;

Figure 6 illustrates a method and computer process according to a first embodiment of the invention with a flow chart presentation;

Figure 7 illustrates a method and computer process according to a second embodiment of the invention; and Figure 8 illustrates a method and computer process according to another embodiment of the invention.

Description of embodiments

With reference to Figure 1 , let us examine an example of communication system 100 in which embodiments of the invention may be applied. The communication system 100 may comprise wireless telecommunication net-

works (WTN#1 ) 102A, (WTN#2) 102B, (WTN#3) 102C, each of which includes a radio access network (RAN#1 ) 104A, (RAN#2) 104B, (RAN#3) 104C.

A wireless telecommunication network 102A to 102C may further comprise a core network (CN#1 ) 106A, (CN#2) 106B, (CN#3) 106C. Parts of the core network 106A to 106C may be shared between the wireless telecommunication networks 102A to 102C.

Each wireless telecommunication network 102A to 102C may be operated by a different network operator.

In an embodiment of the invention, a radio access network 104A to 104C is based on a cellular radio technology, such as GSM (Global System for Mobile Communications), GERAN (GSM/EDGE Radio access network), GPRS (General Packet Radio Service), E-GPRS (EDGE GPRS), UMTS (Universal Mobile Telecommunications System), CDMA2000 (CDMA, Code Division Multiple Access), US-TDMA (US Time Division Multiple Access), TDS-CDMA (Time Division Synchronization CDMA), OFDMA (Orthogonal Frequency Division Multiple Access), HSDPA (High Speed Downlink Packet Access), HSUPA (High Speed Uplink Packet Access) and/or GMR (Geo Mobile Radio).

In an embodiment of the invention, a radio access network 104A to 104C is based on a wireless broadband radio access technology, such as WLAN (Wireless Local Access Network), WiMAX (Worldwide Interoperability for Microwave Access), mobile WiMAX, WiBro (Wireless Broadband Korean), HiperMAN (High Performance Radio Metropolitan Area Network), iBurst (HC- SDMA, High Capacity Spatial Division Multiple Access) and MBWA (802.20, and/or Mobile Broadband Wireless Access). In an embodiment, the radio access networks 104A to 104C are based on different radio access technologies. In an embodiment of the invention, a first radio access network 104A is based on a first cellular radio technology while a second radio access network 104B is based on a first wireless broadband radio access technology. A third radio access network 104C may be based on a second wireless broadband radio access technology or a second cellular radio technology.

In an embodiment of the invention, the first radio access network 104A is based on a first wireless broadband radio access technology, while the second radio access network 104B is based on a second wireless broadband radio access technology different from the first radio access technology. The

third radio access network 104C may be based on a third wireless broadband radio access technology or a cellular radio technology.

A radio access network 104A to 104C may be connected to a public network (PN) 1 10 such as a PLMN (Public Land Mobile Network) or the Inter- net.

Figure 1 further shows a target node 1 12 connectable to the mobile terminal 108 over a wireless telecommunication network 102A to 102C. In an embodiment of the invention, the target node 1 12 is connected to the wireless telecommunication network 102A to 102C via the public network 1 10. The mobile terminal 108 comprises at least one mobile terminal application 114A, 1 14B, 1 14C which involves application data transfer between the mobile terminal 108 and the target node 1 12.

In an embodiment of the invention, the target node 1 12 is a data server. The data server may be an e-mail server, a web-server, a video streaming server, an internet radio server, an instant messaging server and/or a VoIP server (Voice over Internet Protocol).

In another embodiment of the invention, the target node 1 12 is a terminal equipment of a wireless telecommunication system.

In an embodiment of the invention, the mobile terminal application 1 14A to 1 14C is associated with data transfer requirements which define data transfer characteristics required of the communication system 100 for ensuring an efficient operation of the mobile terminal application 114A to 1 14C.

The data transfer requirements comprise at least the following components: - required bandwidth

- transmission delay

- error tolerance.

The data transfer requirement may further include specification relating to the direction of the data transfer requirements. In an embodiment of the invention, the data transfer requirements are relevant in downlink direction. In an embodiment of the invention, the data transfer requirements are relevant in uplink direction.

In another embodiment of the invention, the data transfer requirements are relevant in both directions. In an embodiment of the invention, the mobile terminal application

1 14A to 1 14C involves file download between the target node 1 12 and the

mobile terminal 108. In such a case, the data transfer requirements include strict bandwidth and error tolerance requirements while the transmission delay requirement may be given more freedom. In this case, the requirements are relevant primarily in one communication direction depending on the direction of the application data transfer.

In an embodiment of the invention, the mobile terminal application 114A to 114C is a video conferencing application. In such a case, the mobile terminal requirements may comprise intermediate bandwidth and error tolerance requirements and a high transmission delay requirement. In this case, the requirements are relevant in both directions.

In an embodiment of the invention, the mobile terminal application 114A to 114C involves a streaming application, such as a real-time video streaming application. In such a case, the mobile terminal requirements may comprise high bandwidth and transmission delay requirements, and an inter- mediate error tolerance requirement. In this case, the direction is primarily relevant in downlink direction.

Figure 1 further shows a test node (TN) 116 which may be used for determining data transfer characteristics between the mobile terminal 108 and the target node 112. The test node 116 provides a response to an enquiry transmitted from the mobile terminal 108 so that the mobile terminal 108 is capable of determining the data transfer characteristics from the response.

The test node 116 may be located such that the network between the test node 116 and the target node 112 does not affect the data transfer characteristics. The quality of the network between the test node 116 and the target node 112 may fulfil requirements so that the restrictions in the data transfer capacity can be assumed to arise from wireless telecommunication networks 102A to 102B.

In an embodiment of the invention, the test node 116 is located in the target node 112. Figure 1 further shows a requirement provider node (RPN) 118 which includes a register on the data transfer requirements of the mobile terminal applications 114A to 114C. The mobile terminal 108 may transmit an enquiry for obtaining data transfer requirements of mobile terminal applications 114A to 114C under interest and receives the data transfer requirements as a response to the enquiry.

The enquiry may be based on identification information, such as the Internet Protocol (IP), of the target node 112. The requirement provider node 118 may include a mapping between IP addresses and data transfer requirements associated with each IP address. In an embodiment of the invention, the enquiry is based on identification information of the mobile terminal application 114A to 114C, such as the name of the mobile terminal application 114A to 114C. The requirement provider node 118 may include a mapping between application names and data transfer requirements associated with each application name. Figure 1 further shows price information nodes (PIN#1 ) 120A,

(PIN#2) 120B, (PIN#3) 120C, which include information on application data transfer costs arising from using a specific wireless telecommunication network 102A, 102B, 102C. Each wireless telecommunication network 102A, 102B, 102C may have a price information node 120A to 120C, or the price informa- tion node 120A to 120C may be shared between the wireless telecommunication networks 102A to 102C.

With reference to Figure 2, the mobile terminal 200 comprises a processing unit (PU) 202, a memory unit (MEM) 204 and a user interface (Ul) 206. Figure 2 further shows a first communication unit (COM#1) 208A, a sec- ond communication unit (COM#2) 208B and a third communication unit (COM#3) 208C.

The mobile terminal 200 is a wireless device capable of connecting to a plurality of radio access networks 104A to 104C and capable of running mobile terminal applications 114A to 114C which require application data transfer between the mobile terminal 200 and the target node 112. The mobile terminal 200 may be a mobile phone or a PDA (Personal Digital Assistant), for example.

A communication unit 208A to 208C implements a wireless interface between the mobile terminal 200 and a radio access network 104A to 104C. The communication unit 208A to 208C typically comprises hardware, such as radio frequency parts and analog-to-digital and digital-to-analog components. Some functionalities, such as signal processing and implementation of radio interface protocols, may be implemented with a computer software and a processing unit.

In an embodiment of the invention, at least two communication units 208A to 208C are capable of connecting to a corresponding radio access network 104A to 104C simultaneously.

In an embodiment of the invention, the communication units 208A to 208C implement different radio access technologies. For example, a first communication unit 208A is based on a first cellular radio technology. A second communication unit 208B may be based on a second cellular radio technology or a first wireless broadband radio access technology. A third communication unit 208C may be based on a third cellular radio technology, or a sec- ond wireless broadband radio access technology.

The user interface 206 may comprise a display unit and/or an input device, such as a keypad and/or keyboard.

Figure 3 shows communication units 208A to 208C, mobile terminal applications 114A to 114C, a network analyser (NA) 302, a network selector (NS) 304, a radio interface controller (RIC) 310 and a data router 312.

Figure 4 and 5 shows the network analyser 302, 400 and the network selector 304, 500, respectively, with more details.

The network analyser 302 determines data transfer characteristics between the mobile terminal 300 and the target node 112 in available radio access networks 104A to 104C.

The network selector 304 selects a radio access network 104A to 104C for application data transfer between the mobile terminal 300 and the target node 112 on the basis of a comparison between the data transfer characteristics and data transfer requirements of the mobile terminal applications 114A to 114C communicating with the target node 112.

When selecting the radio access network 104A to 104C, the network selector 304 automatically selects the core network 102A to 102C and parts of the public network 110 associated with the radio access network 104A to 104C. The radio interface controller 310 receives a selection command

318 from the network selector 304, which selection command 318 includes instructions to configure a selected communication unit 208A to 208C to communicate the application data 324A, 324B, 324C between the mobile terminal 300 and the selected wireless telecommunication network 102A to 102C. The radio interface controller 310 may input configuration commands 332A to 332C to the communication units 208A to 208C.

The router 312 receives a routing command 316 from the network selector 304, which routing command 316 includes instructions to configure the router 312 to route the application data 322A to 322C to a selected communication unit 208A to 208C. The router 312 may be implemented with a computer software stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

Let us consider an example where the mobile terminal applications 114A and 114B are active, and the network selector 304 has selected radio access network 102B for communicating the application data 322A and 322B.

The network selector 302 instructs the radio interface controller 310 to activate communication unit 208B compatible with the selected radio access network 102B to communicate with the selected radio access network 102B.

The network selector 302 further instructs the router to route appli- cation data 322A and 322B to the selected communication unit 208B.

In an embodiment of the invention, the network analyzer 302 generates a test signal 308A, 308B, 308C which is inputted into a communication unit 208A to 208C. The network analyzer 400 of Figure 4 may comprise a test signal generator (TSG) 402 for generating the test signals 308A to 308C. Each communication unit 208A to 208B routes the test signal 308A to 308C via its corresponding radio access network 104A to 104C and possibly the core network 106A to 106C to the test node 116. In the example, communication unit 208A routes the test signal 308A via the radio access network 104A, communication unit 208B routes the test signal 308B via the radio ac- cess network 104B, and communication unit 208C routes the test signal 308C via the radio access network 104C.

The test node 116 responds to the test signals 308A to 308C by sending a response signal 326A, 326B, 326C which is received in a corresponding communication unit 208A to 208C. The response signal 326A is a response to the test signal 308A.

The response signal 326B is a response to test the signal 308B.

The response signal 326C is a response to test the signal 308C.

The network analyzer 400 of Figure 4 may comprise a test signal analyzer (TSA) 404 which receives the response signals 326A to 326C and determines the data transfer characteristics of each wireless telecommunication network 102A to 102C. The test signal analyzer 404 may receive test sig-

nal characteristics 406 from the test signal generator 402 and use the test signal characteristics 406 in the determination of the data transfer characteristics. In an embodiment of the invention, the response signal 326A to 326C includes a reception time stamp indicating time-of-arrival of a test signal 308A to 308C to the test node 116. The test signal analyzer 404 may use the reception time stamp for determining uplink data transfer characteristics.

In an embodiment of the invention, the response signal 326A, 326B, 326C includes a transmission time stamp indicating time-of-transmission of the response signal 326A to 326C from the test node 116. The test signal analyzer 404 may use the transmission time stamp for determining downlink data transfer characteristics.

The test signal 308A to 308C may have an address field indicating the test node 116. The test signal 308A to 308C may further include instructions for the test node how to respond to the test signal 308A to 308C. If the test node 116 is located in the target node 112, the test signal 308A to 308C includes the address of the target node 112.

In an embodiment of the invention, the test signal 308A to 308C includes test sequences which are decoded in the test node 116 and copied into the corresponding response signal 326A to 326C. The test signal analyzer 404 may compare the test sequences with original test sequences transmitted in the test signal 308A to 308C. The comparison indicates a bit error rate, for example. In this case, the bit error rate represents a data transfer characteristics. The reception time stamps included in the response signals 326A to 326C may be used for determining uplink transmission delay. In this case, the uplink transmission delay represents data transfer characteristics.

The transmission time stamps included in the response signals 326A to 326C may be used for determining transmission delay in the downlink. In this case, the downlink transmission delay represents data transfer characteristics. The transmission delay between the radio access network 104A to

104C and the test node 116 may be determined from the round-trip time of ping packets transmitted between the radio access network 104A to 104C and the test node 116.

The bandwidth between the radio access network 104A to 104C and the test node 116 may be determined by gradually increasing the size of the ping packets and monitor the throughput time. If the throughput time in-

creases above a threshold, the bandwidth may be considered insufficient for the mobile terminal application 114A, 114B, 114C under interest.

In this case, the downlink bandwidth represents data transfer characteristics. In this case, the uplink bandwidth represents data transfer characteristics.

The transmission of the test signals 308A to 308C further through the communication system 100 may also be used to verify existence of firewalls or other blocking nodes which may reduce the application data transfer. If such a blocking node is detected, the radio access network 104A to 104C may be chosen such that the blocking node does not exist.

The network analyzer 302 feeds determination information 314 to the network selector 304. The determination information 314 includes the data transfer characteristics determined through relevant radio access networks 104A to 104C.

The test signal generator 402 may be implemented with a computer software stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

With reference to Figure 5, the network selector 500 may comprise a register (REG) 502, a comparator (COMP) 504 and a selecting unit (SU) 510.

The register 502 may hold data transfer requirements of the terminal applications 114A to 114C.

In an embodiment of the invention, the register 502 comprises a mapping between the data transfer characteristics and the application names.

In an embodiment of the invention, the register 502 comprises a mapping between the data transfer characteristics and identification information of the target node 112.

The register 502 may be updated with data transfer characteristics when a mobile terminal application 114A to 114C is updated or installed. The mobile terminal application installation file may include the data transfer characteristics or instructions to fetch the data transfer characteristics from the requirement provider node 118.

The data transfer characteristics may further be updated over a ra- dio interface by an operator managing the target node 112.

The comparator 504 may fetch information 506 on the data transfer requirements of a mobile terminal application 114A to 114C under interest and carry out a comparison between the data transfer requirements and the data transfer characteristics associated with each radio access network 104A to 104C.

The comparator 504 inputs comparison results 512 into the selecting unit 510.

In an embodiment of the invention, the selecting unit 510 selects the radio access network 104A to 104C for application data transfer so that the data transfer requirements are met by the data transfer characteristics of a selected radio access network 104A to 104C.

The selecting unit 510 may select a radio access network 104A to 104C for application data transfer, which radio access network 104A to 104C fulfills all the data transfer requirement components, such as required band- width, transmission delay and error tolerance, of the mobile terminal application 1 14A to 114C.

The selecting unit 510 may further verify that the target node 1 12 is not protected by a firewall or other safety measure implemented in the wireless telecommunication networks 102A, 102B, 102C or in the public network 1 10. If none of the radio access networks 104A to 104C fulfill all the data transfer requirement components, the selecting unit 510 may have a priority list which defines data transfer requirement components to be fulfilled. The network selector 304 may select the radio access networks 104A to 104C which fulfills the data transfer requirement components in the top of the priority list. In an embodiment of the invention, the selecting unit 510 selects the radio access network 104A to 104C on the basis of estimated power consumption associated with the use of a radio access network 104A to 104C or costs associated with the use of a radio access network 104A to 104C. The power consumption or cost criteria may occur if there are several candidate radio ac- cess networks 104A to 104C with similar data transfer characteristics. The candidate radio access network 104A to 104C may fulfill one or more data transfer requirement components.

Information on the estimated power consumption may be stored in the memory unit 204 of the mobile terminal 200. The mobile terminal 108, 300 may have an upper power consumption limit which must not be exceeded. In an embodiment, the selecting unit

510 selects the radio access network 104A to 104C whose use is associated with the lowest power consumption.

Cost information on the costs associated with the use of a radio access network 104A to 104C may be stored in the memory unit 204 of the mo- bile terminal. In an embodiment of the invention, the cost information is obtained from the price information node 120A to 120C.

The mobile terminal 108, 300 may have an upper cost limit which must not be exceeded. In an embodiment, the selecting unit 510 selects the radio access network 104A to 104C whose use is associated with the lowest cost.

In an embodiment of the invention, the user interface 206 may receive a command from the user to select the radio access network 104A to 104C if there are several candidate radio access networks 104A to 104C with similar data transfer characteristics. In such a case, the user interface may show the user the power consumption and/or cost information associated with each radio access network 104A to 104C on the basis of which the user may carry out the selection.

In an embodiment of the invention, the selecting unit 510 comprises a user profile which includes priority list relating to selection of the radio access network 104A to 104C. The preference list may include the upper cost limits and power consumption limits, for example. Furthermore, the priority list may define which radio access network 104A to 104C to select if there are several candidate radio access network 104A to 104C. In an embodiment of the invention, the user profile may be modified by the user through the user interface 206.

A selection procedure including determining the data transfer characteristics of candidate wireless telecommunication networks 102A to 102C and selecting the radio access network may be carried out as a background process. The mobile terminal application 114A to 114C may be running, and the application data 322A to 322C may be communicated with the target node by using a current radio access network 104A to 104C. In the meantime, the selection procedure may be running in the background. With this procedure, the mobile terminal 108 selects the most suitable wireless telecommunication network 102A to 102C on the basis of the prevailing data transfer require- ments. The selecting unit 510 may select the radio access network so that no excess data transfer capacity is allocated to the mobile terminal 108.

In an embodiment of the invention, the selection procedure is halted if the data transfer characteristics associated with the currently used radio access network 104A to 104C fulfills predetermined criteria. Such criteria may be the absolute data transfer characteristics or a trend in the data transfer charac- teristics. If the trend shows decrease in the data transfer characteristics due to lowered signal level, for example, the network analyzer 302 may trig the selection procedure. The halting of the selection procedure decreases power consumption in the mobile terminal 300 and decreases the load of the communication system 100. In an embodiment of the invention, the mobile terminal 300 comprises an application analyzer 306 which determines data transfer requirements of the mobile terminal applications 114A to 114C by monitoring the mobile terminal applications 114A to 114C executed in the mobile terminal 300. The application analyzer 306 inputs the information 320 on the data transfer requirements of the mobile terminal applications 114A to 114C to the network selector 304.

In an embodiment of the invention, the application analyzer 306 monitors flow of the application data 322A to 322C and detects measures, such as the maximum or average bandwidth, associated with the mobile ter- minal application 114A to 114C.

In an embodiment of the invention, the network selector 304 obtains the data transfer requirements of the mobile terminal applications 114A to 114C from the requirement provider node 118 by using a communication unit 208A to 208C. The network selector 304 may check the contents of its register 502. If the register 502 fails to provide the data transfer requirements for a mobile terminal application 114A to 114C under interest, the network selector 304 initiates a fetch procedure for obtaining the required the data transfer requirements from the requirement provider node 118.

The register 502 may be implemented with a computer software stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

The comparator 504 may be implemented with a computer software stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

The selecting unit 510 may be implemented with a computer software stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

The application analyser 306 may be implemented with a computer software stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

With reference to Figures 6, 7 and 8, a method and computer process according to embodiments of the invention are shown with flow chart presentation. With reference to Figure 6, the method/computer process starts in

600.

In 602, data transfer characteristics are determined between the mobile terminal 108 and a target node 112 in a plurality of radio access networks 104A to 104C. In 604, a radio access network 104A to 104C is selected for application data transfer between the mobile terminal 108 and the target node 112 on the basis of a comparison between the data transfer characteristics and data transfer requirements of at least one mobile terminal application 114A to 114C communicating with the target node 112. In an embodiment of the invention, 602 and 604 are executed in a background process while a mobile terminal application 114A to 114C is executed.

In 606, it is assessed whether or not further selection criteria are required. If further selection criteria are required, the radio access network is selected in 608 on the basis of estimated power consumption associated with the use of a radio access network 104A to 104C or costs associated with the use of a radio access network 104A to 104C.

In 610, the method/computer process ends. Figures 7 and 8 relate to obtaining data transfer requirements.

With reference to Figure 7, the method/computer process starts in 700.

In 702, it is assessed whether or not data transfer requirements are available.

If data transfer requirements are not available, the data transfer requirements are determined in 704 by monitoring applications 114A to 114C executed in the mobile terminal 108.

In 706, the method/computer process ends. With reference to Figure 8, the method/computer process starts in

800.

In 802, it is assessed whether or not data transfer requirements are available.

If data transfer requirements are not available, the data transfer re- quirements of the at least one application 114A to 114C are obtained from a requirement provider node 118.

In 806, the method/computer process ends.

The computer process may be encoded as a computer program of instructions. The computer program, also referred to as computer software, may be stored in the memory unit 204 and executed in the processing unit 202 of Figure 2.

The computer program may be stored on a computer program distribution medium readable by a computer or a processor. The computer program medium may be, for example but not limited to, an electric, magnetic, optical, infrared or semiconductor system, device or transmission medium. The computer program medium may include at least one of the following media: a computer readable medium, a program storage medium, a record medium, a computer readable memory, a random access memory, an erasable programmable read-only memory, a computer readable software distribution package, a computer readable signal, a computer readable telecommunications signal, computer readable printed matter, and a computer readable compressed software package.

Even though the invention has been described above with reference to an example according to the accompanying drawings, it is clear that the in- vention is not restricted thereto but it can be modified in several ways within the scope of the appended claims.