Radio system and methods for duplex operation

Abstract

A method for duplex telecommunication connection in radio connections is based on a frame-structured interactive communication and a radio system where the frame-structured interactive communication is performed in the radio connections. A means is provided for improving the use of channel resources in implementation of interactive telecommunication connection by providing an FDD connection with one or more TDD dimensions. A full-duplex frequency band is time-duplexed into two or more sub-bands in which interactive communication takes place substantially independently. Transmissions in different transmission directions in each sub-band occur at different times, but simultaneous transmission can occur in different sub-bands in different transmission directions. The message is received entirely in one transmission direction before it needs to be responded to in another transmission direction in a particular sub-band. The frequency band is utilized effectively for communication because transmission can be performed simultaneously in different sub-bands in the reverse transmission directions.

Description

, andReferring also to FIG. 8, an example of the radio system 100 is shown having a base station 102 and a mobile station 104. The base station 102 and mobile station 104 have subsystems 106, 108 to perform various features. It is assumed that a the mobile station 102 of the radio system 100 listens to the Y channel in the subframe df1 of the DL superframe DF1. The mobile station selects a free channel submitted on the Y channel, such as CH1, and sends a random access (RA) message on the free channel CH1 being selected in the subframe uf2 of the UL superframe UF1. A The base station 104 responds by an access grant (AG) message in the subframe df1 of the DL superframe DF2. The AG message informs the mobile station that the channel CH1 has been reserved for it from the next subframe. The mobile station starts transmitting on the channel CH1 in the subframe uf2 of the UL superframe UF2. Since CH1 is now allocated to said mobile station, it is no longer announced through the Y channel in the subframe df1 of the DL superframe DF2. In the above description, the channel allocation takes place by means of the subframe pair df1 and uf2. A similar separate channel allocation can occur simultaneously (but in reverse phase) by means of another subframe pair df2 and uf1. It is possible that the same mobile station participates in the channel allocation in both subframe pairs.

Interactive acknowledgement messages (Y, AG) occur in each sub-frame of a superframe, preferably in the middle of the subframe, whereby the system has enough time to react with the messages. Traffic channels (such as CH1) occur only once in one superframe, i.e. in the present example only in the subframe uf2. In the present example, two connection layers are formed in the frame structure for the interactive messages, one of which is composed of the subframe uf1 of the UL superframes and the subframe df2 of the DL superframes, and correspondingly, the other is composed of the subframe uf2 of the UL superframes and the subframe df1 of the DL superframes. FIG. 5 illustrates the connection layers which are formed in the frame structure. In FIG. 5, solid arrows illustrate interactive communication at a connection level df1-uf2, and dashed arrows illustrate communication at a connection level df2-uf1. It is possible that the same mobile station participates in communication at both connection levels.

By means of the solution of the invention, the allocation situation for each UL subframe is already known in the previous DL subframe and the interactive message concerning each frame address can be transmitted before the next transmission of the frame address in the superframe. For example in the example in FIG. 4, the AG message relating to the RA message submitted in the channel CH1 in the subframe of the superframe UF1 is already submitted in the subframe df1 of the superframe DF2, whereby communication on the channel CH1 can already start in the subframe uf2 of the superframe UF2, the subframe uf2 being the frame wherein the channel CH1 occurs next.

Time-duplexing the connection layer ensures that the information submitted on the Y channel always contains exact information about the free channels in the next subframe. In addition, one AG message in the downlink direction can be employed for responding to all the RA messages at the same connection layer and the AG message can be transmitted to the mobile station before the allocated frame address or allocated frame addresses occur next time in the superframe.

A corresponding example can be presented regarding the aforementioned data transmission acknowledgement. The example is illustrated in FIG. 6. A channel CH2 composed of two UL-frame frame addresses has been reserved for a subscriber for the data transmission. When the data transmission is completed in the subframe uf2 of the superframe UF1, the connection is maintained and the mobile station waits for an ARQ acknowledgement message from the base station. In the case of a successful data transmission, the base station gives the acknowledgement message in the subframe db1 of a DL superframe DF2 and at the same time informs in a Y message that the frame addresses allocated to the channel CH2 are free. In the case of an unsuccessful data transmission, the base station sends a message informing about a transmission failure in the subframe df1 of the superframe DF2, whereby the mobile station can continue transmission on the channel CH2. In both cases, interactive information can be transmitted before the actual traffic channels occur next time in the superframe.

Interactive acknowledgement messages are preferably placed in the middle of the frame, whereby the system is given enough time to react with the information submitted in the previous subframe. If more time is needed in the processing of the messages in the UL and DL directions, as is the case in the systems based on CDMA multiple access technique where the duration of the message comprises the entire frame cycle, the superframe can be composed of more than one subframe. FIG. 7 illustrates the solution of the invention in the case of three subframes (connection layers). The first connection layer is composed of subframes uf2 and df3, the second connection layer is composed of subframes uf3 and df1 and the third connection layer is composed of subframes uf1 and df2. Reaction time has been increased in the case presented in FIG. 7 by delaying the uplink transmission with respect to the downlink transmission by half a frame cycle.

The principles of the invention can also be applied in the conventional time division duplex TDD where the signals in different directions are transmitted interleaved in time on the same transmission channel. In accordance with the invention, the frame in both directions can be composed of two or more subframes, the subframes in turn forming one or more connection layers.

The drawings and the related description are only intended to illustrate the inventive idea. The details of the solution and the frame structure of the invention may vary within the scope of the claims. Although the invention has been described in association with the system based on TDMA multiple access technique by using messages relating to channel allocation as an example, the described solution presented in the invention can also be employed in association with other radio systems using interactive messages.

Claims

1. A method for implementing a duplex telecommunication connection in a radio connections based on interactive communication using data frames in a first transmission direction and in a reverse second transmission direction, each data frame comprising a plurality of frame addresses, and transmission capacity of each radio connection being variable by allocation of frame addresses to it, the method comprising:

composing information of interactive communication in the first transmission direction based on information transmitted in at least two frame addresses of one previous frame in the second transmission direction,

forming the data frames in the first transmission direction and in the second transmission direction from at least two adjacent subframes, each subframe comprising at least two frame addresses,

allocating the subframes in the first and second transmission direction to each interactive communication in such a way that the subframe in the first transmission direction and a subframe in the second transmission direction with allocations to the same interactive communication do not overlap in time, but said subframes may overlap in time with subframes with allocations to another interactive communication.

2. The method of claim 1, wherein the interactive transmission includes an uplink transmission of a random access burst and a downlink transmission of an access grant message as a response.

3. The method of claim 1, wherein the interactive transmission includes data transmission in one direction and a data transmission acknowledgement in another transmission direction.

4. The method of claim 1, wherein communication occurs at several connection layers whose number corresponds to number of subframes.

5. A radio system providing a duplex telecommunication connection in a radio connection based on interactive communication using data frames in a first transmission direction and in a reverse second transmission direction, each data frame comprising a plurality of frame addresses, and properties of each radio connection being variable by allocation of frame addresses to it, wherein the system is arranged to

compose information of interactive communication in the first transmission direction based on information transmitted in at least one previous frame in the second transmission direction,

form the data frames in the first transmission direction and in the second transmission direction from at least two time-adjacent subframes, each subframe comprising at least two frame addresses,

allocate the subframes in said first and second transmission direction to each interactive communication in such a way that the subframe in the first transmission direction and a subframe in the second transmission direction allocated with allocations to the same interactive communication do not overlap in time, but said subframes may overlap in time with subframes with allocations to another interactive communication.

6. The radio system of claim 5 wherein the interactive transmission includes uplink transmission of a random access burst and downlink transmission of an access grant message as a response.

7. The radio system of claim 5 wherein the interactive transmission comprises data transmission in one direction and a data transmission acknowledgement in another transmission direction.

8. The radio system of claim 5 wherein communication occurs at several connection layers whose number corresponds to a number of sub-bands.

9. The method of claim 1 wherein the interactive transmission includes an uplink transmission of a random access burst and a downlink transmission of an access grant message as a response.

10. The method of claim 1 wherein the interactive transmission includes data transmission in one direction and a data transmission acknowledgement in another transmission direction.

11. The method of claim 1 wherein communication occurs at several connection layers whose number corresponds to a number of subframes.

12. The method of claim 1 wherein the duration of a message of said interactive communication corresponds with the cycle of the data frame it is allocated to.

13. The method of claim 1 wherein the data transmission capacity of said radio communication varies corresponding to the number of frame addresses allocated to it.

14. A method for communication comprising:

transmitting a request message in a first frame of a series of frames;

receiving an acknowledgement of the request message;

transmitting data in accordance with the acknowledgement in a second frame of the series of frames,

the first and second frames being next to one another in the series,

the first frame comprising a plurality of frame addresses, the frame addresses being divided among the plurality of the subframes, wherein the request message uses one or more frame addresses of a subframe of the plurality of subframes;

the second frame comprising the plurality of frame addresses repeated from the first frame, the frame addresses being divided among the plurality of subframes, wherein the data uses one or more frame addresses of a subframe of the plurality of subframes;

wherein the receiving step is performed, prior to the one or more frame addresses used by the request message being repeated in the second frame.

15. The method of claim 14 wherein the acknowledgment is in the middle of a third frame that is not part of the series of frames.

16. The method of claim 14, wherein the first and second frames are uplink frames.

17. The method of claim 16, wherein the is received in a third frame that is a downlink frame.

18. The method of claim 17 wherein the first and second frames are transmitted by a mobile unit and the third frame is received from a base station.

19. The method of claim 14, wherein the acknowledgement indicates that one or more frame addresses in an uplink direction are available.

20. A method for communication comprising:

receiving, in a downlink direction, a message in a first downlink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe the first subframe including the message, the message identifying which uplink frame address or addresses are free;

transmitting, in an uplink direction, a request message in a first uplink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the second subframe including the request message, the request message requesting one or more of the identified uplink frame address or addresses, the request message occupying one or more frame addresses of the second subframe;

receiving, in the downlink direction, an allocation message in a second downlink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the first subframe including the allocation message, the allocation message allocating the requested uplink frame address or addresses, the first subframe being received prior to the recurrence of the one or more frame addresses occupied by the request message; and

transmitting, in the uplink direction, data in a second uplink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the second subframe including the data within the allocated frame address or addresses,

wherein the first and second downlink frames are next to one another in a series of downlink frames and the first and second uplink frames are next to one another in a series of downlink frames.

21. The method of claim 20, wherein the message identifying which uplink frame address or addresses are free is a Yell message.

22. The method of claim 20, wherein the request message is a RACH message.

23. The method of claim 20, wherein the allocation message is an access grant message.

24. The method of claim 20, wherein the allocated frame address or addresses constitute a data channel.

25. A method for communication comprising:

transmitting, in an uplink direction, data in a first uplink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the second subframe including the data on an allocated channel, the allocated channel occupying one or more frame addresses of the second subframe;

receiving, in a downlink direction, a message in a downlink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the first subframe including a message indicating that the data has not been received, the first subframe being received prior to the recurrence of the one or more frame addresses used by the allocated channel; and

transmitting, in the uplink direction, data in a second uplink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the second subframe including a repetition of the data on the allocated channel.

26. A method for communication comprising:

transmitting, in an uplink direction, data in a first uplink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the second subframe including the data on an allocated channel, the allocated channel occupying one or more frame addresses of the second subframe;

receiving, in a downlink direction, a message in a downlink frame comprising a plurality of frame addresses, the plurality of frame addresses being divided into a first subframe and a second subframe, the first subframe including a message acknowledging the data, the first subframe being received prior to the recurrence of the one or more frame addresses used by the allocated channel; and

releasing the allocated channel for use in a second uplink frame immediately following the first uplink frame, the frame addresses of the allocated channel being available for use prior to their recurrence in the second uplink frame.