WO2005060300A1

WO2005060300A1 - Wireless system comprising a first station and a second station system

Info

Publication number: WO2005060300A1
Application number: PCT/IB2004/052660
Authority: WO
Inventors: Wolfgang Otto Budde; Salvador Expedito Boleko Ribas; Joachim Kahlert; Francesc Dalmases
Original assignee: Philips Intellectual Property & Standards Gmbh; Koninklijke Philips Electronics N. V.
Priority date: 2003-12-15
Filing date: 2004-12-03
Publication date: 2005-06-30

Abstract

Wireless systems like wireless local/wide area networks and wireless personal area networks comprising first stations (1) and second station systems (5,7,9) like wireless terminals and access points suffer from radio interference and range limitation. To be able to guarantee a quality of service to a relatively large extent, a first radio channel (30) is used for exchanging a first part of information and simultaneously a second radio channel (40) is used for exchanging a second part of this information, which different physical radio channels (30,40) are defined by different channel frequencies. Channel addings and/or replacings make the wireless systems more flexible. Detectors (12,52,72,112) for detecting link parameters like amounts of missing information, error rates and/or signal strengths support the channel addings and/or replacings. The information comprises packetised information messages, with a packetised control message defining the radio channels (30,40) to be used. Each first station (1) and each second station system (5,7,9) comprises two interfaces (25,26,65,66,85,86,125,226) for interfacing the radio channels (30,40).

Description

Wireless system comprising a first station and a second station system

The invention relates to a wireless system comprising a first station and a second station system for exchanging information between the first station and the second station system via at least one radio channel, and also relates to a first station, to a transmitter, to a first method, to a first processor program product, to a second station system, to a receiver, to a second method, and to a second processor program product, all for exchanging information between the first station and the second station system via the at least one radio channel. Examples of such a wireless system are wireless local/wide area networks and wireless personal area networks. Examples of such stations and station systems are wireless terminals and access points in wireless local/wide area networks and wireless personal area networks.

A prior art wireless system is known from US 2003/0012217, which discloses a wireless system comprising channel type switching. In dependence of an amount of data to be exchanged, one out of a few communication channels of different types can be switched. For a smaller amount of data to be exchanged, a common radio channel is used. In case of a larger amount of data to be exchanged, the prior art wireless system switches to a dedicated radio channel and uses this channel. To reduce undesirable channel type switching resulting from strongly fluctuating amounts of data to be exchanged, the prior art wireless system detects a parameter affecting a decision whether to switch. Wireless systems suffer from radio interference and range limitation. These impairments lead to radio channel degradation. This problem cannot always be solved by switching from one radio channel to an other radio channel, due to, for certain kinds of radio interference, like wide band interference, and for range limitation, all available radio channels degrading under these conditions. As a result, a quality of service can only be guaranteed to a relatively limited extent. The prior art wireless system is disadvantageous, inter alia, due to guaranteeing a quality of service to a relatively limited extent.

It is an object of the invention, inter alia, to provide a wireless system which can guarantee a quality of service to a relatively large extent. Further objects of the invention are, inter alia, to provide a first station, a transmitter, a first method, a first processor program product, a second station system, a receiver, a second method, and a second processor program product, which all can guarantee a quality of service to a relatively large extent. The wireless system according to the invention comprises a first station and a second station system for exchanging information between the first station and the second station system via at least one radio channel, which first station comprises a transmitter for simultaneously using - a first radio channel for transmitting a first part of the information; and - a second radio channel for transmitting a second part of the information; and which second station system comprises a receiver for simultaneously using - the first radio channel for receiving the first part of the information; and - the second radio channel for receiving the second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. By providing the first station with the transmitter and by providing the second station system with the receiver, the information to be exchanged is spread over two different radio channels, and as a result the first part and the second part of the information are exchanged via these two different radio channels in parallel. As a result, a quality of service can now be guaranteed to a relatively large extent, due to each radio channel only guiding a part of the information. Per first/second radio channel used, the available bandwidth will not be used completely for the first/second part of the information, which allows the first/second parts of information to be exchanged such that (additional) protection measures can be used. Thereto, for example, an original piece of information to be exchanged at an original bit rate via an original channel is now divided into the first part of information and the second part of information, with each first second part of information to be exchanged at half the original bit rate via its own first/second radio channel, to reduce the influence of disturbances and to gain more time for an improved reconstruction, without having reduced the overall bit rate. Or, for example, an original piece of information to be exchanged via an original channel is now divided into the first part of information and the second part of information, with each first/second part of information to be exchanged in combination with (stronger/longer) first/second error correcting codes via its own first/second radio channel, to reduce the influence of disturbances and to increase the redundancy for an improved reconstruction, without having reduced the overall information density between the first station and the second station system. Further, under the condition that the disturbances allow this, the wireless system according to the invention may be operated at a reduced signal strength, which introduces an advantageous decrease of interference from this wireless system in neighbouring areas (increased frequency re-use factor). Each radio channel mentioned is a physical radio channel and should not be confused with a virtual radio channel. The first radio channel is located at/around a first channel frequency and the second radio channel is located at/around a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The first radio channel may be an original radio channel, with the second radio channel being the added channel, or vice versa. Alternatively, both the first radio channel and the second radio channel may be added channels to be added to an original channel, or both the first radio channel and the second radio channel may together replace an original channel, in which latter cases both the first radio channel and the second radio channel not only differ from each other but also differ from this original channel. So, the adding of two or more new radio channels to one or more original radio channels is not to be excluded. Further, the replacing of two or more original channels by three or more new radio channels and all kinds of combinations of channel addings and replacings are not to be excluded either. These channel addings and/or replacings increase the flexibility of the wireless system. An embodiment of the wireless system according to the invention is defined by the first station comprising a wireless terminal and the second station system comprising a further wireless terminal. In this case, a communication takes place between two wireless terminals. An embodiment of the wireless system according to the invention is defined by the first station comprising a wireless terminal and the second station system comprising one access point. In this case, a communication takes place between a wireless terminal and an other terminal via one access point. An embodiment of the wireless system according to the invention is defined by the first station comprising a wireless terminal and the second station system comprising two access points. In this case, a communication takes place between a wireless terminal and an other terminal via two access points, with a first access point being used for the first radio channel and a second access point being used for the second radio channel. An embodiment of the wireless system according to the invention is defined by further comprising a detector for detecting a link parameter for, in dependence of a detection result, selecting at least one of the first radio channel and the second radio channel to be used. By detecting the link parameter with respect to one or more original radio channels and in response making one or more channel addings and/or replacings, the quality of service can be detected and, in response to a detection result, one or more channel addings and/or replacings can be made. An embodiment of the wireless system according to the invention is defined by the link parameter comprising an amount of missing information, an error rate and/or a signal strength. These link parameters, without excluding further parameters, are good indications for the quality of service. An embodiment of the wireless system according to the invention is defined by the information comprising packetised information messages, with the first part of the information comprising first packetised information message parts and with the second part of the information comprising second packetised information message parts. These packetised information messages allow the spreading of the information over the radio channels per message or per message part advantageously. Usually, each packetised information message part comprises data information and overhead information. An embodiment of the wireless system according to the invention is defined by the information further comprising at least one packetised control message for defining at least one of the first radio channel and the second radio channel to be used. The packetised control message defines at least the one or more new radio channels to be added and/or one or more new radio channels replacing one or more original radio channels advantageously, and is transmitted from the first station to the second station system and/or vice versa. The packetised control message may comprise packetised control message parts and allows the spreading over the radio channels per message or per message part advantageously. Usually, a control message message part does not comprise data information, but only comprises overhead information. An embodiment of the wireless system according to the invention is defined by the first station and the second station system each comprising a first interface for interfacing the first radio channel and a spreader for dividing the information into the first part of the information and the second part of the information and a second interface for interfacing the second radio channel and a despreader for combining the first part of the information and the second part of the information. These interfaces each comprise for example one or more units like filters, amplifiers, attenuators, forks etc. Some of these units may need to be (adaptively) tuned to the corresponding channel frequency. The first station according to the invention for exchanging information between the first station and a second station system via at least one radio channel is defined by comprising a transmitter for simultaneously using - a first radio channel for transmitting a first part of the information; and - a second radio channel for transmitting a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The transmitter according to the invention for use in a first station for exchanging information between the first station and a second station system via at least one radio channel is defined by being adapted to simultaneously use - a first radio channel for transmitting a first part of the information; and - a second radio channel for transmitting a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The first method according to the invention for exchanging information between a first station and a second station system via at least one radio channel is defined by comprising a transmitting step for simultaneously using a first radio channel for transmitting a first part of the information; and - a second radio channel for transmitting a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The first processor program product according to the invention for use in combination with a first station for exchanging information between the first station and a second station system via at least one radio channel is defined by comprising a transmitting function for simultaneously using a first radio channel for transmitting a first part of the information; and - a second radio channel for transmitting a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The second station system according to the invention for exchanging information between a first station and the second station system via at least one radio channel is defined by comprising a receiver for simultaneously using - a first radio channel for receiving a first part of the information; and - a second radio channel for receiving a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The receiver according to the invention for use in a second station system for exchanging information between a first station and the second station system via at least one radio channel is defined by being adapted to simultaneously use - a first radio channel for receiving a first part of the information; and - a second radio channel for receiving a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The second method according to the invention for exchanging information between a first station and a second station system via at least one radio channel is defined by comprising a receiving step for simultaneously using - a first radio channel for receiving a first part of the information; and - a second radio channel for receiving a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. The second processor program product according to the invention for use in combination with a second station system for exchanging information between a first station and the second station system via at least one radio channel is defined by comprising a receiving function for simultaneously using - a first radio channel for receiving a first part of the information; and - a second radio channel for receiving a second part of the information; which first radio channel is defined by a first channel frequency and which second radio channel is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other. Embodiments of the first station, the transmitter, the first method, the first processor program product, the second station system, the receiver, the second method, and the second processor program product correspond with the embodiments of the wireless system according to the invention. The invention is based on the insight, inter alia, that radio channel degradation of one radio channel sometimes cannot be avoided by switching from this one radio channel to an other radio channel, and is based on the basic idea, inter alia, that the use of two radio channels in parallel offers more possibilities to overcome the radio channel degradation. The invention solves the problem, inter alia, of providing a wireless system which can guarantee a quality of service to a relatively large extent, and is advantageous, inter alia, in that protection measures can be used without reducing an overall bit rate and/or an overall information density between the stations. Further, under the condition that the disturbances allow this, a decrease of the interference with neighbouring areas (increased frequency re-use factor) can be introduced, by operating the wireless system according to the invention at a reduced signal strength. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments(s) described hereinafter. In the drawings:

Fig. 1 shows a wireless system according to the invention comprising two wireless terminals; Fig. 2 shows a wireless system according to the invention comprising a wireless terminal and an access point; and Fig. 3 shows a wireless system according to the invention comprising a wireless terminal and two access points.

The wireless system according to the invention shown in Fig. 1 comprises a first station 1 in the form of a wireless terminal, which first station 1 comprises a processor system 10 coupled to a man-machine-interface 11 or mmi 11 and to a transmitter-receiver 2. Processor system 10 comprises a detector 12 and further comprises for example a memory not shown. The transmitter-receiver 2 comprises a spreader 22 of which an input is coupled to the processor system 10. A first output of the spreader 22 is coupled via a first modulator 24 to an input of a first interface 25 which is further coupled to a first antenna. A second output of the spreader 22 is coupled via a second modulator 23 to an input of a second interface 25 which is further coupled to a second antenna. The transmitter-receiver 2 further comprises a despreader 29 of which an output is coupled to the processor system 10. A first input of the despreader 29 is coupled via a first demodulator 28 to an output of the first interface 25. A second input of the despreader 29 is coupled via a second demodulator 27 to an output of the second interface 25. The processor system 10 is further coupled via control connections not shown to the spreader 22 and the despreader 29 for controlling the spreading and the despreading, and is further coupled via control connections not shown to the modulators 23,24, the demodulators 27,28 and the interfaces 25,26 for controlling the modulating and the demodulating and the channel frequencies of a first radio channel 30 and of a second radio channel 40 to be used via the antennas. The wireless system according to the invention shown in Fig. 1 comprises a second station system 5 in the form of a wireless terminal, which second station system 5 comprises a processor system 50 coupled to a man-machine-interface 51 or mmi 51 and to a transmitter-receiver 6. Processor system 50 comprises a detector 52 and further comprises for example a memory not shown. The transmitter-receiver 6 comprises a spreader 62 of which an input is coupled to the processor system 50. A first output of the spreader 62 is coupled via a first modulator 64 to an input of a first interface 65 which is further coupled to a first antenna. A second output of the spreader 62 is coupled via a second modulator 63 to an input of a second interface 65 which is further coupled to a second antenna. The transmitter-receiver 6 further comprises a despreader 69 of which an output is coupled to the processor system 50. A first input of the despreader 69 is coupled via a first demodulator 68 to an output of the first interface 65. A second input of the despreader 69 is coupled via a second demodulator 67 to an output of the second interface 65. The processor system 50 is further coupled via control connections not shown to the spreader 62 and the despreader 69 for controlling the spreading and the despreading, and is further coupled via control connections not shown to the modulators 63,64, the demodulators 67,68 and the interfaces 65,66 for controlling the modulating and the demodulating and the channel frequencies of the first radio channel 30 and of the second radio channel 40 to be used via the antennas. During a single channel phase, the first station 1 and the second station system 5 are communicating with each other via for example the first radio channel 30, in which case in the transmitter-receiver 2 only the first modulator 24 and the first interface 25 and the first demodulator 28 are used, with the spreader 22 and the despreader 29 being deactivated, and in which case in the transmitter-receiver 6 only the first modulator 64 and the first interface 65 and the first demodulator 68 are used, with the spreader 62 and the despreader 69 being deactivated. Via the first radio channel 30, information is exchanged between the first station 1 and the second station system 5. This information for example comprises packetised information messages. The detector 12 (or 52) regularly detects one or more link parameters, like for example amounts of missing information in the form of for example a number of missing acknowledge messages, error rates in the form of for example amounts of missing information per time interval, received signal strengths etc. These link parameters are good indications for the quality of service. As soon as one or more link parameters are on the wrong side of one or more borderlines, the quality of service can no longer be guaranteed. In response, the processor system 10 (or 50) takes action by selecting for example the second radio channel 40 to be added to the first channel 30 and by generating for example a packetised control message defining this second radio channel 40 to be added. This packetised control message is sent via the first channel 30 from the first station 1 (or the second station system 5) to the second station system 5 (or the first station 1). In response to this packetised control message, the processor systems 10 and 50 activate their spreaders 22 and 62 and their despreaders 29 and 69, and the next phase is entered. During a dual channel phase, the first station 1 and the second station system 5 are communicating with each other via for example the first radio channel 30 and the second radio channel 40 simultaneously, in which case in the transmitter- receiver 2 now for example both modulators 23 and 24 and both interfaces 25 and 26 and both demodulators 27 and 28 are used, with the spreader 22 and the despreader 29 now being activated, and in which case in the transmitter-receiver 6 now for example both modulators 63 and 64 and both interfaces 65 and 66 and both demodulators 68 and 69 are used, with the spreader 62 and the despreader 69 now being activated. Via the first radio channel 30 and the second radio channel 40, information is exchanged between the first station 1 and the second station system 5. This information is now divided into a first part of information to be exchanged via the first radio channel 30, and a second part of the information to be exchanged via the second radio channel 40. In case of the information comprising packetised information messages, the first part of the information comprises first packetised information message parts and the second part of the information comprises second packetised information message parts. These packetised information messages allow the spreading of the information over the radio channels 30 and 40 per message or per message part advantageously. Thereto, the spreaders 22 and 62 and the despreaders 29 and 69 have been activated: the spreaders 22 and 62 for example supply the odd packetised messages or the odd packetised message parts or the first ten packetised message parts etc. to the first modulators 24 and 64, and supply the even packetised messages or the even packetised message parts or the next ten packetised message parts etc. to the second modulators 23 and 63. Alternatively, packets may be assigned to one or the other radio channel according to their relation to certain applications, or their transmit priority, size or any other parameter. After receival and demodulation by the first demodulators 28 and 68 and the second demodulators 27 and 67, the despreaders 29 and 69 combine the packetised messages or the packetised message parts etc. Finally, either the communication between the first station 1 and the second station system 5 is over, resulting in for example a packetised control message being generated, or the detector 12 (or 52) has detected that the link parameters are again on the right side of the borderlines, in response to which the processor system 10 (or 50) takes action by selecting for example the second radio channel 40 to be deleted and by generating for example the packetised control message defining this second radio channel 40 to be deleted. This packetised control message is sent via either the first channel 30 or the second radio channel 40 or partly via the first channel 30 and partly via the second radio channel 40 from the first station 1 (or the second station system 5) to the second station system 5 (or the first station 1). In response to this packetised control message, the processor systems 10 and 50 deactivate their spreaders 22 and 62 and their despreaders 29 and 69, and the next single channel phase is entered, etc. By providing the first station 1 with the transmitter-receiver 2 and by providing the second station system 5 with the transmitter-receiver 6, the information to be exchanged is spread over two different radio channels 30 and 40, and as a result the first part and the second part of the information are exchanged via these two different radio channels 30 and 40 in parallel. As a result, a quality of service can now be guaranteed to a relatively large extent, due to each radio channel 30,40 only guiding a part of the information. Per first/second radio channel 30,40 used, the available bandwidth will not be used completely for the first/second part of the information, which allows the first/second parts of information to be exchanged such that (additional) protection measures can be used. Thereto, for example, an original piece of information to be exchanged at an original bit rate via an original channel is now divided into the first part of information and the second part of information, with each first/second part of information to be exchanged at half the original bit rate via its own first/second radio channel, to reduce the influence of disturbances and to gain more time for an improved reconstruction, without having reduced the overall bit rate. Or, for example, an original piece of information to be exchanged via an original channel is now divided into the first part of information and the second part of information, with each first/second part of information to be exchanged in combination with

(stronger/longer) first/second error correcting codes via its own first/second radio channel 30,40, to reduce the influence of disturbances and to increase the redundancy for an improved reconstruction, without having reduced the overall information density between the first station 1 and the second station system 5. Further, under the condition that the disturbances allow this, the wireless system according to the invention may be operated at a reduced signal strength, which introduces an advantageous decrease of interference from this wireless system in neighbouring areas (increased frequency reuse factor). Each radio channel 30,40 mentioned is a physical radio channel and should not be confused with a virtual radio channel. The first radio channel 30 is located at/around a first channel frequency and the second radio channel 40 is located at/around a second channel frequency, which first channel frequency and which second channel frequency are different from each other. Each processor system 10,50 may further comprise a generator not shown for generating packetised control messages and an activator-deactivator for activating-deactivating the spreaders 22,62 and the despreaders 29,69. The first radio channel 30 may be an original radio channel, with the second radio channel 40 being the added channel, or vice versa. Alternatively, both the first radio channel 30 and the second radio channel 40 may be added channels to be added to an original channel, or both the first radio channel 30 and the second radio channel 40 may together replace an original channel, in which latter cases both the first radio channel 30 and the second radio channel 40 not only differ from each other but also differ from this original channel. So, the adding of two or more new radio channels to one or more original radio channels is not to be excluded. Further, the replacing of two or more original channels by three or more new radio channels and all kinds of combinations of channel addings and replacings are not to be excluded either. In a minimum situation, the first station 1 comprises only the transmitter part of the transmitter-receiver 2, then comprising the spreader 22, both modulators 23,24 and both interfaces 25,26, and the second station system 5 only comprises the receiver part of the transmitter-receiver 6, then comprising the despreader 69, both demodulators 67,68 and both interfaces 65,66. In this case, for example mmi 11 comprises a (mobile) camera for monitoring an object, and the pictures of the object are sent to the mmi 51 for example comprising a display for showing the pictures to a user. These pictures may be sent all the time via both radio channels 30,40 in parallel, which may result in an inefficient use of the available radio channels, or the pictures are sent at first via the first radio channel 30 only, with the processor system 10 comprising the detector 12 for detecting one or more link parameters for making channel addings and/or replacings. The packetised control message is sent via the first radio channel 30 from the first station 1 to the second station system 5. In this case, due to the first station 1 now not being able to receive information from the second station system 5, the detector 12 will comprise a sensor for detecting for example environment noise. In a more extended situation, the first station 1 further comprises one demodulator 28, and the second station system 5 further comprises one modulator 64. In this case, for example mmi 11 comprises a (mobile) camera for monitoring an object, and the pictures of the object are sent to the mmi 51 for example comprising a display and a keyboard for showing the pictures to a user, which user now has the option of controlling the camera via the first radio channel 30. These pictures again may be sent all the time via both radio channels 30,40 in parallel, which may result in an inefficient use of the available radio channels, or the pictures are sent at first via the first radio channel 30 only, with the processor system 10 comprising the detector 12 for detecting one or more link parameters for making channel addings and/or replacings, and/or with the processor system 50 comprising the detector 52 for detecting one or more link parameters for making channel addings and/or replacings. The packetised control message is sent via the first radio channel 30 from the first station 1 to the second station system 5 or vice versa. In a maximum situation, the first station 1 further also comprises the other demodulator 27 and the despreader 29, and the second station system 5 further also comprises the other modulator 63 and the spreader 62. Each mmi 11,51 for example comprises a microphone, a keyboard, a display, a loudspeaker, a camera etc. for allowing two users to make audio/video calls with each other. In Fig. 1 two wireless terminals communicate directly with each other. However, this is not the only option. Alternatively, an access point may be involved, with a communication between two terminals taking place via this access point. Or, one wireless terminal may communicate via the access point with a fixed network coupled to this access point. Such an access point is shown in Fig. 2. The wireless system according to the invention shown in Fig. 2 comprises a first station 1 as already described for Fig. 1 and comprises a second station system 7 in the form of an access point. The second station system 7 comprises a processor system 70 coupled to a transmitter-receiver 8 and to fixed network couplings 73,74,75. Processor system 70 comprises a detector 72 and further comprises for example a memory not shown. The transmitter-receiver 8 comprises a spreader 82 of which an input is coupled to the processor system 70. A first output of the spreader 82 is coupled via a first modulator 84 to an input of a first interface 85 which is further coupled to a first antenna. A second output of the spreader 82 is coupled via a second modulator 83 to an input of a second interface 85 which is further coupled to a second antenna. The transmitter-receiver 8 further comprises a despreader 89 of which an output is coupled to the processor system 70. A first input of the despreader 89 is coupled via a first demodulator 88 to an output of the first interface 85. A second input of the despreader 89 is coupled via a second demodulator 87 to an output of the second interface 85. The processor system 70 is further coupled via control connections not shown to the spreader 82 and the despreader 89 for controlling the spreading and the despreading, and is further coupled via control connections not shown to the modulators 83,84, the demodulators 87,88 and the interfaces 85,86 for controlling the modulating and the demodulating and the channel frequencies of the first radio channel 30 and of the second radio channel 40 to be used via the antennas. In case of a communication between the first station 1 and a third station not shown taking place via the second station system 7 in the form of the access point, the first station 1 and the third station communicate with the access point 7 via the radio channels 30 and 40 in a time-sharing manner, whereby channel addings and/or replacings may take place as described before. In case of a communication between the first station 1 and a fourth station not shown taking place via this access point 7 and one or more of the fixed network couplings 73,74,75, the first station 1 communicates with the access point 7 via the radio channels 30 and 40, and the access point 7 communicates with this fourth station via the fixed network couplings 73,74,75. Therefore, processor system 70 will further comprise one or more switches and/or switching functions etc. The wireless system according to the invention shown in Fig. 3 comprises a first station 1 as already described for Fig. 1 and comprises a second station system 9 in the form of two access points 100,200. The second station system 9 comprises a first access point 100 for example operating at 2.4 GHz and comprising a first processor system 110 coupled to a first transmitter-receiver 120 and to a spreader 122 and to a despreader 129 and to fixed network couplings 93,94,95. The first processor system 110 comprises a detector 112 and further comprises for example a memory not shown. The first transmitter-receiver 120 comprises a first modulator 124 coupled to a first interface 125 which is further coupled to a first antenna and to a first demodulator 128. The first processor system 110 is further coupled via control connections not shown to the first modulator 124, the first demodulator 128 and the first interface 125 for controlling the modulating and the demodulating and the channel frequencies of the first radio channel 30 to be used via the first antenna. The second station system 9 further comprises a second access point 200 for example operating at 5 GHz and comprising a second processor system 210 coupled to a-second transmitter- receiver 220 and to the fixed network couplings 93,94,95. The second processor system 210 comprises for example a memory not shown. The second transmitter-receiver 220 comprises a second modulator 223 coupled to a second interface 226 which is further coupled to a second antenna and to a second demodulator 227. The second processor system 210 is further coupled via control connections not shown to the second modulator 223, the second demodulator 227 and the second interface 226 for controlling the modulating and the demodulating and the channel frequencies of the second radio channel 40 to be used via the second antenna. During a single channel phase, the first station 1 and the first access point 100 are communicating with each other via for example the first radio channel 30, in which case in the transmitter-receiver 2 only the first modulator 24 and the first interface 25 and the first demodulator 28 are used, with the spreader 22 and the despreader 29 being deactivated, with the spreader 122 and the despreader 129 being deactivated. Via the first radio channel 30, information is exchanged between the first station 1 and the first access point 100. The detector 12 (or 112) regularly detects one or more link parameters. As soon as one or more link parameters are on the wrong side of one or more borderlines, the quality of service can no longer be guaranteed. In response, the processor system 10 (or 110) takes action by selecting for example the second radio channel 40 to be added to the first channel 30 and by generating for example a packetised control message defining this second radio channel 40 to be added. This packetised control message is sent via the first channel 30 from the first station 1 (or the first access point 100) to the first access point 100 (or the first station 1) and is also sent via the fixed network couplings 93,94,95 to the second access point 200. In response to this packetised control message, the processor systems 10 and 110 activate their spreaders 22 and 122 and their despreaders 29 and 129, and the next phase is entered. During a dual channel phase, the first station 1 is communicating simultaneously with the first access point 100 via for example the first radio channel 30 and with the second access point 200 via the second radio channel 40. Via the first radio channel 30 and the second radio channel 40, information is exchanged between the first station 1 and the second station system 9. This information is now divided into a first part of information to be exchanged via the first radio channel 30, and a second part of the information to be exchanged via the second radio channel 40. In case of the information comprising packetised information messages, the first part of the information comprises first packetised information message parts and the second part of the information comprises second packetised information message parts. Before transmission and modulation, the spreaders 22 and 122 divide the information into the first and second information parts, whereby, for spreader 122, the first information parts are modulated in and transmitted by the first access point 100, and the second information parts are supplied via the fixed network couplings 93,94,95 to the second access point 200 for being modulated and transmitted. After receival and demodulation, the despreaders 29 and 129 combine the information parts, whereby, for despreader 129, the first information parts have arrived via the first access point 100, and the second information parts have arrived via the second access point 200 and the fixed network couplings 93,94,95 etc. as described before. Alternatively, the fixed network couplings 93,94,95 between the access points 100,200 may be replaced by one or more radio channels. Further alternatively, a communication may take place between the first station 1 and the third station not shown but mentioned before via the first access point 100 serving both wireless terminals in a time-sharing manner, whereby the wireless terminals may negotiate with each other to (look for and) add the second access point 200 to this communication. This second access point 200 will then serve both wireless terminals in a time-sharing manner, and these wireless terminals then communicate with each other via two different radio channels, with each access point 100,200 then serving a different radio channel, without any interaction taking place between these access points 100,200. But independently of how many access points are involved and of whether there is an interaction between these access points or not, generally, the wireless terminals will negotiate the distribution of information via the radio channels. In each station and in each station system shown, each interface for example comprises one or more units like filters, amplifiers, attenuators, forks etc. Some of these units may need to be (adaptively) tuned to the corresponding channel frequency. Further, some of these units may need to be (adaptively) tuned to the modulation-demodulation technology used. So, each modulator and each demodulator may use a fixed modulation-demodulation technology, with the different radio channels using the same or different modulation-demodulation technologies, or each modulator and each demodulator may use one out of two or more different modulation- demodulation technologies, to be adjusted by the corresponding processor system. Each processor system may further adjust the spreader and the despreader for adjusting spreading-despreading technologies. Instead of two antennas, one common antenna may be used for both interfaces in a station. Functions of units shown in the Figures may be shifted to neighbouring units, for example the spreaders and the despreaders may be integrated into the corresponding processor systems. Further units not shown may be present, like for example the generator and the activator-deactivator and the memory discussed before, and like for example buffers, mixers, further modulators and demodulators etc. The construction of each station and of each station system, especially but not exclusively of the access point, may have many embodiments. Units shown and not shown may comprise hardware, software or a mixture of both. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

CLAIMS:

1. Wireless system comprising a first station (1) and a second station system (5,7,9) for exchanging information between the first station (1) and the second station system (5,7,9) via at least one radio channel, which first station (1) comprises a transmitter (2) for simultaneously using - a first radio channel (30) for transmitting a first part of the information; and - a second radio channel (40) for transmitting a second part of the information; and which second station system (5,7,9) comprises a receiver (6,8,120+220) for simultaneously using - the first radio channel (30) for receiving the first part of the information; and - the second radio channel (40) for receiving the second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

2. Wireless system as defined in claim 1, wherein the first station (1) comprises a wireless terminal and the second station system (5) comprises a further wireless terminal.

3. Wireless system as defined in claim 1, wherein the first station (1) comprises a wireless terminal and the second station system (7) comprises one access point.

4. Wireless system as defined in claim 1, wherein the first station (1) comprises a wireless terminal and the second station system (9) comprises two access points.

5. Wireless system as defined in claim 1, further comprising a detector (12,52,72,112) for detecting a link parameter for, in dependence of a detection result, selecting at least one of the first radio channel (30) and the second radio channel (40) to be used.

6. Wireless system as defined in claim 5, wherein the link parameter comprises an amount of missing information, an error rate and/or a signal strength.

7. Wireless system as defined in claim 1, wherein the information comprises packetised information messages, with the first part of the information comprising first packetised information message parts and with the second part of the information comprising second packetised information message parts.

8. Wireless system as defined in claim 7, wherein the information further comprises at least one packetised control message for defining at least one of the first radio channel (30) and the second radio channel (40) to be used.

9. Wireless system as defined in claim 1, wherein the first station (1) and the second station system (5,7,9) each comprise a first interface (25,65,85,125) for interfacing the first radio channel (30) and a spreader (22,62,82,122) for dividing the information into the first part of the information and the second part of the information and a second interface (26,66,86,226) for interfacing the second radio channel (40) and a despreader (29,69,89,129) for combining the first part of the information and the second part of the information.

10. First station (1) for exchanging information between the first station (1) and a second station system (5,7,9) via at least one radio channel, which first station (1) comprises a transmitter (2) for simultaneously using - a first radio channel (30) for transmitting a first part of the information; and - a second radio channel (40) for transmitting a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

11. Transmitter (2) for use in a first station (1) for exchanging information between the first station (1) and a second station system (5,7,9) via at least one radio channel, which transmitter (2) is adapted to simultaneously use a first radio channel (30) for transmitting a first part of the information; and - a second radio channel (40) for transmitting a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

12. First method for exchanging information between a first station (1) and a second station system (5,7,9) via at least one radio channel, which first method comprises a transmitting step for simultaneously using - a first radio channel (30) for transmitting a first part of the information; and a second radio channel (40) for transmitting a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

13. First processor program product for use in combination with a first station (1) for exchanging information between the first station (1) and a second station system (5,7,9) via at least one radio channel, which first processor program product comprises a transmitting function for simultaneously using a first radio channel (30) for transmitting a first part of the information; and a second radio channel (40) for transmitting a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

14. Second station system (5,7,9) for exchanging information between a first station (1) and the second station system (5,7,9) via at least one radio channel, which second station system (5,7,9) comprises a receiver (6,8,120+220) for simultaneously using - a first radio channel (30) for receiving a first part of the information; and - a second radio channel (40) for receiving a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

15. Receiver (6,8) for use in a second station system (5,7,9) for exchanging information between a first station (1) and the second station system (5,7,9) via at least one radio channel, which receiver (6,8) is adapted to simultaneously use a first radio channel (30) for receiving a first part of the information; and - a second radio channel (40) for receiving a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

16. Second method for exchanging information between a first station (1) and a second station system (5,7,9) via at least one radio channel, which second method comprises a receiving step for simultaneously using a first radio channel (30) for receiving a first part of the information; and - a second radio channel (40) for receiving a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.

17. Second processor program product for use in combination with a second station system (5,7,9) for exchanging information between a first station (1) and the second station system (5,7,9) via at least one radio channel, which second processor program product comprises a receiving function for simultaneously using a first radio channel (30) for receiving a first part of the information; and a second radio channel (40) for receiving a second part of the information; which first radio channel (30) is defined by a first channel frequency and which second radio channel (40) is defined by a second channel frequency, which first channel frequency and which second channel frequency are different from each other.