Patent Application
20090213800
(a) Field of the Invention
The present invention relates to a state controlling apparatus and method in a cellular system. More particularly, the present invention relates to a terminal state controlling apparatus and method in a 3rd Generation Partnership Project (3GPP) system.
(b) Description of the Related Art
In a cellular system, a terminal has two types of operational modes, an idle mode for saving terminal power and network resource and for providing a seamless service and a connected mode for data communication between the terminal and the base station. A transition between these two operational modes is achieved by a control of a radio resource control (hereinafter, referred to as “RRC”) layer belonging to a network layer in a protocol structure. Accordingly, a delay may be generated on the transmission of control instructions. In addition, the control instruction delay may generate a control channel allocation and recovery delay, where the control channel is involved in a channel allocation and a shared channel allocation for data transmission in a packet system. Since the channel allocation and recovery operation of the connected mode-terminal is performed by all terminals in the same manner, a control physical channel may be continuously maintained even when there are a small number of packet data to be transmitted or a desired quality of service (QoS) of a packet data is low, thereby increasing power consumption. In a conventional connection for terminal-initial access and paging processes, the random access process is performed through the same algorithm, and accordingly, the same delay may be generated. Thus, a priority-connection may be not performed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
The present invention has been made in an effort to provide a state controlling apparatus and method in a cellular system having advantages of determining a terminal state transition according to packet service characteristics and an available radio resource state.
An exemplary embodiment of the present invention provides a terminal state controlling method including transiting a terminal into a dormant state when packet data are not received from the terminal in an active state for a predetermined time, and transiting the terminal into an idle state when packet data to be transmitted to the terminal in the dormant state are not received for a predetermined time. At this time, the active state and the dormant state are states in which the uplink and downlink traffic channels are allocated to the terminal, the active state being a state in which the terminal maintains a synchronization to the uplink and downlink traffic channels and the dormant state being a state in which the terminal breaks the synchronization to the uplink and downlink traffic channels. The idle state is a state in which the uplink and downlink traffic channels are not allocated to the terminal. The dormant state may be a state in which the terminal discontinuously receives the packet data through the downlink traffic channel.
Another embodiment of the present invention provides a terminal state controlling method transiting a terminal into a scheduling-OFF state when packet data are not received from the terminal in a scheduling-ON state for a predetermined time, and transiting a terminal into a dormant state when packet data are not received from the terminal in the scheduling-OFF state for a predetermined time. At this time, the scheduling-ON state, the scheduling-OFF state, and the dormant states are states in which uplink and downlink traffic channels are allocated to the terminal, the scheduling-ON state being a state in which the uplink and downlink traffic channel resources are allocated to the terminal according to the terminal-supportable QoS, the scheduling-OFF state being a state in which the terminal discontinuously transmits/receives the packet data through the uplink and downlink traffic channels, and the dormant state being a state in which the terminal breaks a synchronization to the uplink and downlink traffic channels.
Meanwhile, the terminal state controlling method may include: allocating a state transition channel to the terminal in the scheduling-OFF state; receiving a state transition request for transiting the terminal from the scheduling-OFF state to the scheduling-ON state; and transiting the terminal from the scheduling-OFF state to the scheduling-ON state when the state transition request is received. Meanwhile, the terminal state controlling method may include: determining a random access channel resource according to the terminal-supportable QoS; informing the determined random access channel resource of the terminal through a paging channel; receiving a transition request into the active state from the terminal in the dormant state through the determined random access channel resource; and transiting the terminal from the dormant state to the scheduling-ON state or the scheduling-OFF state when the transition request is received.
In the following detailed description, only certain exemplary embodiments of the present invention have been shown and described, simply by way of illustration. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.
Throughout this specification and the claims which follow, unless explicitly described to the contrary, the word “comprise” or variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.
A cellular system according to an exemplary embodiment of the present invention uses a pilot channel, a paging channel, a state transition channel, a random access channel (RACH), a downlink traffic channel, and a uplink traffic channel.
The pilot channel is a downlink control channel used such that the terminal achieves synchronization with the base station.
The paging channel is a downlink control channel used such that the base station pages the terminal or transmits an instruction to the terminal.
The state transition channel is a bi-directional control channel used such that the base station exchanges state transition information with the terminal.
The random access channel is a uplink control channel used for the terminal to broadcast information to the base station by competing other terminals through a backoff time determined according to a regular rule.
The downlink traffic channel is a data channel used such that the base station transmits traffic data to the terminal and the uplink traffic channel is a data channel used such that the terminal transmits traffic data to the base station.
That is, the cellular system according to an exemplary embodiment of the present invention uses the pilot channel, paging channel, state control channel, and random access channel as the control channel and uses the downlink traffic channel and uplink data channel as the data channel.
Now, a state controlling method and apparatus of a cellular system according to an exemplary embodiment of the present invention will be described with reference to the accompanying figures.
As shown in
Dislike
A protocol structure of a state controlling apparatus according to an exemplary embodiment of the present invention will be described with reference to
As shown in
The physical layer I measures a radio channel state and supports wireless transmission technology of the cellular system. The data link layer II is placed on the physical layer I and performs a division and re-combination of user data transmitted through the physical layer I, and controls the state of the terminal 300 based on characteristics of packet service of the transmitted data. The data link layer II Includes a media access control layer (hereinafter, a “MAC layer”) and a wireless link control layer. The network layer III sets a wireless bearer such that it performs a transmission of the control instruction and user data between the terminal 300 and the core network 100. The network layer III includes a radio resource control layer (hereinafter, referred to as a “RRC layer”). The RRC layer controls a terminal operational state transition by controlling establishment and termination of a RRC connection, which is a passage for exchanging the control information between the terminal 300 and the core network 100.
The state controlling apparatus according to an exemplary embodiment of the present invention will be described with reference to
As shown in
The RRC transmitting buffer 420 and the MAC transmitting buffer 450 are for storing packet data to be transmitted to the terminal 300. In more detail, the RRC layer III receives packet data to be transmitted to the terminal 300 and stores the same to the RRC transmitting buffer 420. The RRC layer BI transmits the packet data of the RRC transmitting buffer 420 to the MAC layer II. The MAC layer II receives the packet data and stores the same to the MAC transmitting buffer 450, and transmits the stored packet data of the MAC transmitting buffer 450 through the physical layer I to the terminal 300.
The RRC receiving buffer 430 and the MAC receiving buffer 460 are for storing the packet data received from the terminal 300. In more detail, the MAC layer II receives the packet data through the physical layer I from the terminal 300 and stores the same to the MAC receiving buffer 460. The MAC layer II transmits the stored packet data of the MAC receiving buffer 460 to the RRC layer III, and the RRC layer III stores the transmitted packet data to the RRC receiving buffer 430. The stored packet data of the RRC receiving buffer 430 are transmitted through the core network 100 to a destination.
The resource manager 410 manages a resource allocation to the terminal 300, and monitors the RRC transmitting buffer 420 and the RRC receiving buffer 430. The scheduler 440 performs a scheduling for the terminal 300, and monitors the MAC transmitting buffer 450 and the MAC receiving buffer 460.
A terminal state managed by a cellular system according to an exemplary embodiment of the present invention will be described with reference to
As shown in
The connected state 500 includes an active state 510 and a dormant state 520. The terminal 300 in the active state 510 maintains synchronization to the downlink traffic channel and the uplink traffic channel. Accordingly the terminal 300 in the active state 510 may exchange traffic data with the state controlling apparatus 400. The terminal 300 in the dormant state 520 may reduce power consumption by breaking synchronization to the downlink traffic channel and the uplink traffic channel. In addition, the terminal 300 in the dormant state 520 may further reduce the power consumption by receiving traffic data through the downlink traffic channel according to a discontinuous reception (DRX) scheme. According to the DRX scheme, the terminal 300 may reduce the power consumption because the terminal 300 accesses to the downlink traffic channel at a time slot negotiated with the state controlling apparatus 400. The terminal 300 in the dormant state 520 uses a random access channel so as to transmit control information to the state controlling apparatus 400. The state controlling apparatus 400 uses a paging channel so as to transmit control information to the terminal 300 in the dormant state 520.
The active state 510 includes a scheduling-ON state 511 and a scheduling-OFF state 512. The state controlling apparatus 400 allocates resources of the downlink and uplink traffic channels to the terminal 300 in the scheduling-ON state 511 according to the QoS. That is, the state controlling apparatus 400 performs a scheduling to the plurality of terminals and allocates a radio resource determined according to the QoS to the respective terminals. Meanwhile, the terminal 300 in the scheduling-OFF state 512 operates the control channel and the data channel in the DRX scheme or DTX (discontinuous transmission) scheme. Particularly, the terminal 300 in the scheduling-OFF state 512 uses the downlink traffic channel of the DRX scheme and the uplink traffic channel of the DTX scheme. That is, the terminal 300 In the scheduling-OFF state 512 discontinuously receives traffic data through the downlink traffic channel and discontinuously transmits the same through the uplink traffic channel to the state controlling apparatus 400. Resultantly, the terminal 300 consumes more power in the scheduling-ON state 511 than in the scheduling-OFF state 512. In order to rapidly transit the terminal 300 from the scheduling-OFF state 512 to the scheduling-ON state 511, the state controlling apparatus 400 allocates a state transition channel to the terminal 300 in the scheduling-OFF state 512. The terminal 300 in the scheduling-OFF state 512 may use the state transition channel in the DRX scheme and the DTX scheme.
The terminal 300 in the idle state 600 may not exchange the traffic data with the state controlling apparatus 400 and performs a synchronization to the pilot channel and the paging channel. The terminal 300 in the idle state 600 may access to the random access channel. The state controlling apparatus 400 recovers the downlink and uplink traffic channels from the terminal 300 in the idle state 600 and manages the radio resource. Accordingly, the terminal 300 in the idle state 600 may not maintain synchronization to the downlink and uplink traffic channels, so that it may reduce power consumption.
How the state controlling apparatus 400 controls a state of the terminal 300 according to an exemplary embodiment of the present invention will now be described with reference to
First, how the state controlling apparatus 400 transits the terminal 300 from the active state 510 to the dormant state 520 will be described with reference to
For description of
The resource manager 410 monitors the RRC receiving buffer 430, determines that the RRC receiving buffer 430 is empty for a predetermined time (S103, S105), and transits the terminal 300 from the active state 510 to the dormant state 520 (S107). The resource manager 410 provides state transition information to the terminal 300 while it transits the terminal 300 to the dormant state 520, and accordingly, it allows the corresponding terminal 300 to break synchronization to the uplink traffic channel and allocates the discontinuous time slots of the downlink traffic channel to the corresponding terminal 300. Accordingly, the transited terminal 300 in the dormant state 520 may receive traffic data discontinuously through the downlink traffic channel. However, it may not perform a synchronization to the uplink traffic channel, and accordingly, it may not transmit traffic data to the state controlling apparatus 400.
In addition, the resource manager 410 may transit the terminal 300 to the dormant state 520 because it is difficult to allocate a radio resource due to a deteriorated wireless environment between the terminal 300 and the base station 220, or may transit the terminal 300 to the dormant state 520 for other reasons.
How the state controlling apparatus 400 transits the terminal 300 from the dormant state 520 to the active state 510 will now be described with reference to
First, the resource manager 410 determines a resource of the random access channel according to the terminal-supportable QoS (S201). At this time, the resource of the random access channel may be a backoff time or the like.
The resource manager 410 informs the determined random access channel resource information of the terminal 300 through the paging channel (S203).
The terminal in the dormant state 520 requests the resource manager 410 to transit the terminal to the active state 510 through the informed random access channel (S205).
And then, the resource manager 410 transits the corresponding terminal 300 to the active state 510 (S207). The resource manager 410 transmits state transition information through the paging channel to the terminal 300 while transiting the terminal 300 to the active state 510 (S209), and accordingly, it allows the terminal 300 to perform synchronization to the uplink traffic channel.
First, the terminal 300 is in the dormant state 520 (S301).
The resource manager 410 monitors the RRC transmitting buffer 420 (S303), determines that the RRC transmitting buffer 420 stores more packet data than a predetermined reference amount and transits the terminal 300 to the active state 510 (S305). The resource manager 410 transmits the state transition information through the paging channel to the terminal 300 while transiting the terminal 300 to the active state 510 (S307) such that the terminal 300 performs a synchronization to the uplink traffic channel.
Next, how the state controlling apparatus 400 transits the terminal 300 from the connected state 500 to the idle state 600 will be described. The resource manager 410 transits the terminal from the connected state 500 to the idle state 600 when the RRC transmitting buffer 420 and the RRC receiving buffer 430 are empty for a predetermined time.
Next, how the state controlling apparatus 400 transits the terminal 300 from the idle state 600 to the connected state 500 will be described. The resource manager 410 confirms that the packet data are input to the RRC transmitting buffer 420 and transits the terminal 300 from the idle state 600 to the connected state 500. Meanwhile, the terminal 300 in the idle state 600 confirms that there is packet data to be transmitted to the state controlling apparatus 400, requests the state controlling apparatus 400 to transit the terminal 300 to the connected state 500 through the random access channel, and is transited to the connected state 500.
As described above, the resource manager 410 controls the state transition between the active state 510 and the dormant state 520 and controls the state transition between the connected state 500 and the idle state 600. The resource manager 410 controls the resource allocation according to the terminal-supportable Qos and thus manages the radio resource.
Next, how the state controlling apparatus 400 transits the terminal 300 from the scheduling-ON state 511 to the scheduling-OFF state 512 will be described with reference to
First, the terminal 300 is in the scheduling-ON state 511 (S401). At this time, the scheduler 440 allocates resources of the uplink traffic channel and the downlink traffic channel to the terminal 300 in the scheduling-ON state 511 according to the terminal-supportable QoS.
The scheduler 440 determines whether the QoS level of the stored packet data of the MAC transmitting buffer 450 exceeds a predetermined threshold QoS (S403). If the QoS level of the stored packet data of the MAC transmitting buffer 450 exceeds a predetermined threshold QoS, the scheduler 440 maintains the terminal 300 in the scheduling-ON state 511. However, if the QoS level of the stored packet data of the MAC transmitting buffer 450 is lower than the predetermined threshold QoS, the scheduler 440 determines whether the stored packet data amount of the MAC transmitting buffer 450 and the MAC receiving buffer 460 is more than the predetermined threshold traffic amount (S405). If the stored packet data amount of the MAC transmitting buffer 450 and the MAC receiving buffer 460 is more than the predetermined threshold traffic amount, the scheduler 440 maintains the terminal 300 in the scheduling-ON state 511. However, if the stored packet data amount of the MAC transmitting buffer 450 and the MAC receiving buffer 460 is lower than the predetermined threshold traffic amount, it transits the terminal 300 to the scheduling-OFF state 512 (S407). When the stored packet data amount of the MAC transmitting buffer 450 and the MAC receiving buffer 460 is lower than the predetermined threshold traffic amount, the terminal 300 may exchange the packet data with the state controlling apparatus 400 through part of time slots of the downlink and uplink traffic channels. The scheduler 440 controls the corresponding terminal 300 such that the terminal in the scheduling-OFF state 512 discontinuously transmits/receives packet data through the uplink and downlink traffic channels.
When the terminal 300 does not broadcast the packet data, the terminal 300 may be transited from the active state 510 to the dormant state 520. The scheduling-OFF state 512 may utilize a temporary state of such a transition process. That is, the scheduler 440 transits the terminal 300 from the scheduling-ON state 511 to the scheduling-OFF state when the MAC receiving buffer 460 is empty for a predetermined time. Thereafter, when the MAC receiving buffer 460 is empty for a predetermined time, the RRC receiving buffer 430 may be empty for a predetermined time. Accordingly, the resource manager 410 transits the terminal 300 from the scheduling-OFF state 512 to the dormant state 520.
Next, how the state controlling apparatus 400 transits the terminal 300 from the scheduling-OFF state 512 to the scheduling-ON state 511 will be described with reference to
First, the terminal 300 Is in the scheduling-OFF state 512 (S501).
The scheduler 440 allocates a state transition channel to the terminal 300 in the scheduling-OFF state 512 so as to rapidly transit the terminal 300 to the scheduling-ON state 511 (S503) and the terminal 300 in the scheduling-OFF state 512 maintains a synchronization to the state transition channel.
The scheduler 440 confirms that the QoS level of the packet data of the MAC transmitting buffer 450 is higher than the threshold QoS (S505), and transits the terminal 300 to the scheduling-ON state 511 (S509). In addition, the scheduler 440 confirms that the stored packet data amount of the MAC transmitting buffer 450 and the MAC receiving buffer 460 is more than the predetermined threshold traffic amount (S507), and transits the terminal 300 to the scheduling-ON state 511 (S509).
The scheduler 440 transmits the state transition information to the terminal 300 through the state transition channel, in which the state transition information includes that the terminal is transited to the scheduling-ON state 511 (S511) such that the terminal 300 cancels the DRX scheme applied to the downlink traffic channel. In addition, the terminal 300 receives the state transition information and cancels the DRX scheme applied to the downlink traffic channel.
First, the terminal 300 is in a scheduling-OFF state 512 (S601).
The scheduler 440 allocates the state transition channel to the terminal 300 in the scheduling-OFF state 512 (S603), and the terminal 300 in the scheduling-OFF state 512 maintains a synchronization to the state transition channel.
When the terminal 300 requires a higher QoS than that of the scheduling-OFF state 512 (S605), it requests the state controlling apparatus 400 to transit the terminal 300 into the scheduling-ON state 511 through the state transition channel (S609). In addition, when the terminal 300 wants to transmit more packet data than that which the terminal 300 in the scheduling-OFF state 512 can transmit to the state controlling apparatus 400 (S607), the terminal 300 requests the state controlling apparatus 400 to transit the state of the terminal 300 into the scheduling-ON state 511 through the state transition channel (S609).
When the scheduler 440 receives the state transition request to the scheduling-ON state 511 (S609), it transits the terminal 300 from the scheduling-OFF state 512 to the scheduling-ON state 511 (S611), and allocates the uplink and downlink traffic channel radio resource to the terminal 300 according to the requested QoS.
The scheduler 440 transmits the state transition information that the terminal 300 is transited into the scheduling-ON state 511 to the terminal 300 through the state transition channel (S613), and allows the terminal 300 to cancel the DRX scheme applied to the downlink traffic channel. In addition, the terminal 300 receives the state transition information and cancels the DRX scheme applied to the downlink traffic channel.
According to the exemplary embodiments of the present invention, the dormant state 520 is defined as a state in which the terminal 300 breaks a synchronization to the backward traffic channel. However, it may be defined as a state in which the terminal 300 may not transmit the packet data even though the terminal 300 maintains a synchronization to the uplink traffic channel. At this time, the state transition channel may be used so as to transmit the state transition information between the base station 220 and the terminal 300.
The state controlling apparatus 400 according to the exemplary embodiments of the present invention may be formed in the base station 220, and may be formed in the wireless network subsystem 200a of
The constituent elements described in the exemplary embodiments of the present invention may be realized as hardware formed with such a logic element as at least one DSP (digital signal processor), a processor, a controller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), other electronic apparatuses, or a combination thereof. At least some functions or processes according to the exemplary embodiments of the present invention may be realized as software, which may be recorded in a recording medium. In addition, the constituent elements, functions, or processes described according to the exemplary embodiments of the present invention may be realized as a combination of hardware and software.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
According to the exemplary embodiments of the present invention, the terminal state may be controlled according to the format and QoS of the packet service, and thus it is possible to efficiently use a radio resource and to reduce power consumption. It is possible to rapidly transit the terminal state by controlling the terminal state in the data link layer.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2005-0051523 | Jun 2005 | KR | national |
| 10-2006-0053527 | Jun 2006 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2006/002292 | 6/15/2006 | WO | 00 | 3/23/2009 |
