WO2012053841A2

WO2012053841A2 - Method and apparatus for transmitting and receiving data in wireless access system supporting machine to machine communication

Info

Publication number: WO2012053841A2
Application number: PCT/KR2011/007838
Authority: WO
Inventors: Jeongki Kim; Giwon Park; Youngsoo Yuk
Original assignee: Lg Electronics Inc.
Priority date: 2010-10-20
Filing date: 2011-10-20
Publication date: 2012-04-26
Also published as: WO2012053841A3

Abstract

The present disclosure relates to a method of allowing an MTC terminal to transmit and/or receive data to and/or from a network entity in a wireless access system supporting machine type communication (MTC), and the method may include receiving an MTC operating parameter from the network entity; and transmitting and/or receiving data to and/or from the network entity based on the received MTC operating parameter, wherein the MTC operating parameter includes a first power saving interval for prohibiting access to the network entity, a first active interval for allowing access to the network entity, a second power saving interval, and a second active interval, and the second power saving interval and the second active interval are located within the first active interval, and repeated within the first active interval.

Description

METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING DATA IN WIRELESS ACCESS SYSTEM SUPPORTING MACHINE TO MACHINE COMMUNICATION

The present disclosure relates to a wireless access system supporting machine-to-machine communication, and more particularly, to a method and apparatus for transmitting and receiving data between an MTC terminal and a network entity.

M2M communication (machine type communication; MTC)

Hereinafter, machine-to-machine (M2M) communication (or machine type communication (MTC)) will be described in brief.

Machine-to-machine (M2M) communication may denote communication between an electronic device and an electronic device as its expression. In other words, M2M communication may denote communication between objects. In general, M2M communication may denote wired or wireless communication between electronic devices or communication between a human-controlled device and a machine, but it may be also used as a meaning of particularly referring to wireless communication between an electronic device and an electronic device, namely, between machines. M2M terminals used in a cellular network may have lower performance or capability than that of typical terminals.

A lot of terminal may exist within a cell, and those terminal may be distinguished from one another based on its type, class, service, and the like.

For example, based on their operation type, terminals may be largely classified into a human type communication (HTC) terminal and a machine type communication (MTC) terminal. The machine type communication (MTC) may include communication between M2M terminals. Here, human type communication (HTC) may denote the transmission and reception of signals for which the transmission of signals is determined by a human, whereas MTC may denote the transmission of signals triggered by itself or event occurrence in each terminal or periodically without the intervention of a human.

Furthermore, if machine-to-machine (M2M) communication (or machine type communication (MTC)) is taken into consideration, then the number of whole terminals may suddenly increase. M2M terminal may have the following features based on support services.

1. A lot of terminal within a cell

2. Low amount of data

3. Transmission of low frequency (may have periodicity)

4. Limited number of data characteristics

5. Insensitive to time delay

6. Having low mobility or fixed

Furthermore, M2M communication may be used in various fields, such as protected access and surveillance, pursuit and discovery, public safety (emergency situation, disaster), payment (vending machine, ticket machine, parking meter), health care, remote control, smart meter, and the like.

MTC feature time-controlled traffic

A time-controlled MTC feature may be provided for the use of MTC applications defined to transmit or receive data only during a defined time interval and avoid unnecessary signalling during an interval other than the defined time interval. A network operator may differently assign to traffic occurrence, thus allowing the MTC applications to transmit and receive data or activate signalling during an interval other than the defined time interval.

The defined access interval (for example, 10 minutes) has been agreed in advance between a network operator and an MTC terminal (subscriber), which is a sufficiently long period of time to secure the completion of normal communication between an MTC terminal and an MTC server.

An MTC terminal does not have to wait until the access interval is completed to release connection to an MTC server when communication with the MTC server is finished.

FIG. 1 is a view illustrating an example of a defined time interval assigned to an MTC terminal having a time-controlled traffic feature.

In general, an MTC user may agree (or make an appointment) a defined period of time in advance with an operator for a group of MTC terminals. A time for allowing access may be referred to as a grant time interval 110, and a time for disallowing access may be referred to as a forbidden time interval 120. Furthermore, a time for actually performing communication during the grant time interval may be referred to as a communication window 130.

Network may communicate with an MTC terminal during the grant time interval and also communicate with an MTC user and MTC server during the grant time interval. The "grant time interval" does not overlap with the "forbidden time interval" in which access is forbidden.

In general, a communication window for 5-10 minutes may be sufficient for each MTC terminal. A network operator may limit an interval of the communication window. In order to avoid network overload, signalling and data traffic in the communication window of MTC terminals may be distributed into a predefined period of time (for example, by randomizing a start time of each communication window).

Idle mode

Idle mode is a mechanism capable of periodically receiving a downlink broadcast message without registering with a specific base station even when a terminal wanders in a wireless link environment having a plurality of base stations over a wide region.

Idle mode is a state in which only downlink synchronization is carried out to suspend all normal operations as well as handover (HO), and receive a paging message which is a broadcast message only for a predetermined interval. Paging message is a message for indicating paging action to a terminal. For example, the paging action may include ranging operation, network reentry, and the like.

Idle mode may be initiated by a terminal or initiated by a base station. In other words, the terminal may transmit a deregistration request (DREG-REQ) message to the base station, and receive a deregistration response (DREG-RSP) message in response to the deregistration request (DREG-REQ) message, thereby entering an idle mode. Furthermore, the base station may transmit a deregistration request (DREG-REQ) message or deregistration command (DREG-CMD) to the terminal, thereby entering an idle mode.

When the terminal receives a paging message corresponding to the terminal itself during an available interval (AI), the terminal may be switched to a connected mode through a network entry process with the base station to transmit and receive data.

Sleep mode

In a sleep mode operation, a terminal requests to enter into a sleep mode if there exists no more traffic to be transmitted and/or received to and/or from a base station while performing a communication with the base station in an active mode, and receives a response to that request from the base station to change the state thereof to a sleep mode.

The terminal that has entered into a sleep mode state receives a message indicating whether there exists a traffic transferred from the base station during a sleep listening window, and determines that there exists no data traffic transmitted to a downlink when negative indication indicating that there exists no traffic is received.

Furthermore, if positive indication is received from the base station during the listening window, then the terminal determines that there exists data traffic transferred to a downlink, and initializes the current sleep cycle. At this time, the type of data traffic that can be received by a terminal may be a real time or non-real time service, and it has a feature that packet data transmitted and/or received to and/or from the terminal will have non-periodicity if a non-real time service is received such as short message, and packet data transmitted and/or received to and/or from the terminal will have periodicity if a real time service is received such as VoIP (Voice on IP).

Hereinafter, a typical sleep mode operation will be described in brief.

A terminal performs communication with a base station in a normal or active mode, and transmits a sleep-request (SLP-REQ) message for entering into a sleep mode to the base station if there exists no more traffic to be transmitted and/or received to and/or from the base station.

The base station receives the SLP-REQ message from the terminal, transmits a sleep-response (SLP-RSP) message to the terminal in response to the SLP-REQ message.

The SLP-RSP message may include a sleep mode parameter for operating the sleep mode of a terminal, such as a sleep cycle, a listening window, and the like. The terms, "listening section" and "sleep interval", used below shall have the same meaning as "listening window" and "sleep window", respectively.

According to circumstances, even without the sleep-request message of the terminal (S101), the base station may directly transmit an unsolicited SLP-RSP message to the terminal, thereby instructing the terminal to enter a sleep mode.

The terminal that has received a SLP-RSP message from the base station changes the state to a sleep mode by referring to a sleep operating parameter to perform a sleep mode operation.

The sleep mode may include a sleep window (SW) incapable of receiving data and a listening window (LW) capable of receiving data.

In the sleep mode, the base station transmits a traffic-indication (TRF-IND) message to the terminal to indicate whether or not there exists traffic to be transferred to the terminal during a listening window.

The TRF-IND message indicating the existence or non-existence of the traffic is set to positive indication if there exists traffic, but set to negative indication if there exists no traffic. If a positive TRF-IND message is received, then the terminal transmits or receives the generated data traffic during the listening window, and enters the sleep window (SW) to perform a sleep mode operation.

The power consumption of machine-to-machine (M2M) or machine type communication (MTC) terminals should be minimized.

In particular, for a time controlled feature in an M2M or MTC system, a specific access duration has been assigned in advance to an M2M terminal to transmit and receive data during a specific period of time, and the relevant M2M terminal should be operated in a connected mode to perform communication with an M2M server or base station during the duration.

However, the access duration may continue up to several tens of seconds or several minutes, and if traffic for the M2M terminal occurs during only part of the duration, then the M2M terminal being operated in a connected mode during the access duration may increase unnecessary power consumption of the M2M terminal. If the timing of generating a packet within the access duration is different, in other words, a packet is generated at the start of the access duration or in the middle of the access duration, then the M2M terminal being operated in a connected mode prior to the timing of generating the packet may produce an unnecessary power consumption.

Accordingly, an object of the present disclosure is to provide a method for minimizing the power consumption of M2M terminals having a time-controlled traffic feature in an M2M or MTC system.

According to the present disclosure, there is provided a method of allowing an MTC terminal to transmit and/or receive data to and/or from a network entity in a wireless access system supporting machine type communication (MTC), and the method may include receiving an MTC operating parameter from the network entity; and transmitting and/or receiving data to and/or from the network entity based on the received MTC operating parameter, wherein the MTC operating parameter includes a first power saving interval for prohibiting access to the network entity, a first active interval for allowing access to the network entity, a second power saving interval, and a second active interval, and the second power saving interval and the second active interval are located within the first active interval, and repeated within the first active interval.

Furthermore, the method may be characterized in that said transmitting and receiving data includes performing a network re(entry) process with the network entity, and then operating in a power saving mode; receiving first indication information or data indicating that traffic occurs during the second active interval from the network entity; switching from the power saving mode to an active mode, and transmitting and/or receiving data to and/or from the network entity in the active mode.

Furthermore, the method may be characterized by further including extending the first active interval or maintaining an active mode during the first power saving interval when data transmission and reception with the network entity is not completed at the completion timing of the first active interval.

Furthermore, the method may be characterized by further including receiving second indication information indicating that traffic occurrence is completed or a mode change indicator indicating mode change from the network entity; and switching from the active mode to the power saving mode.

Furthermore, the method may be characterized in that the power saving mode is a sleep mode or idle mode supported in an 802.16 system.

Furthermore, the method may be characterized in that when the power saving mode is a sleep mode, the first and the second power saving interval correspond to a first sleep window (SW1) and a second sleep window (SW2), respectively, and the first and the second active interval correspond to a first listening window (LW1) and a second listening window (LW2), respectively.

Furthermore, the method may be characterized in that when the power saving mode is an idle mode, the first and the second power saving interval correspond to a first unavailable interval (UAI1) and a second unavailable interval (UAI2), respectively, and the first and the second active interval correspond to a first available interval (AI1) and a second available interval (AI2), respectively.

Furthermore, the method may be characterized in that the MTC operating parameter is received through the network re(entry) process.

Furthermore, the method may be characterized in that the network entity is a base station (BS).

Furthermore, the method may be characterized in that the MTC terminal has a time-controlled traffic feature.

Furthermore, the method may be characterized in that data transmitted and/or received to and/or from the network entity during the first active interval is unicast data.

Furthermore, the method may be characterized in that the power saving mode is a mode for turning off the power of the MTC terminal or exchanging basic information with the network entity.

Furthermore, the method may be characterized in that the basic information is information required for the M2M terminal to perform synchronization with the network entity, system information, multicast/broadcast data, or a downlink (DL) signal.

Furthermore, according to the present disclosure, there is provided a terminal for transmitting and/or receiving data to and/or from a network entity in a wireless access system supporting machine type communication (MTC), and the terminal may include a wireless communication unit configured to transmit and/or receive radio signals to and/or from the outside; and a controller connected to the wireless communication unit, wherein the controller controls the wireless communication unit to receive an MTC operating parameter from the network entity, and controls the wireless communication unit to transmit and/or receive data to and/or from the network entity based on the received MTC operating parameter, and the MTC operating parameter includes a first power saving interval for prohibiting access to the network entity, a first active interval for allowing access to the network entity, a second power saving interval, and a second active interval, and the second power saving interval and the second active interval are located within the first active interval, and repeated within the first active interval.

Furthermore, the terminal may be characterized in that the controller controls the wireless communication unit to receive first indication information or data indicating that traffic occurs during the second active interval in a power saving mode from the network entity, and controls the wireless communication unit to switch from the power saving mode to an active mode, and transmit and/or receive data to and/or from the network entity in the active mode.

Furthermore, the terminal may be characterized in that the controller controls to extend the first active interval or maintain an active mode during the first power saving interval when data transmission and reception with the network entity is not completed at the completion timing of the first active interval.

Furthermore, the terminal may be characterized in that the controller controls the wireless communication unit to receive second indication information indicating that traffic occurrence is completed or a mode change indicator indicating mode change from the network entity, and controls to switch from the active mode to the power saving mode.

Furthermore, it may be characterized in that the terminal is a machine-to-machine (M2M) terminal or machine type communication (MTC) terminal.

Furthermore, it may be characterized in that the terminal has a time-controlled traffic feature.

According to the present disclosure, a plurality of power saving intervals and active intervals may be assigned to M2M or MTC terminals to define a new mechanism in which the terminals operate in a connected mode only during an interval in which data is actually transmitted and received, and operate in a power saving mode during an interval other than the interval, thereby obtaining an effect of minimizing the power consumption of M2M or MTC terminals.

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

In the drawings:

FIG. 1 is a view illustrating an example of a defined time interval assigned to an M2M terminal having a time-controlled traffic feature;

FIG. 2 is a conceptual view illustrating a wireless communication system to which an embodiment of the present disclosure is applicable;

FIG. 3 is a flow chart illustrating a method of transmitting and receiving data between an MTC terminal and a base station according to an embodiment of the present disclosure;

FIG. 4 is a view illustrating a power saving interval and an active interval according to an embodiment of the present disclosure;

FIG. 5 is a flow chart illustrating the operation of an M2M terminal during a power saving interval and an active interval according to an embodiment of the present disclosure;

FIG. 6 is a view illustrating a case of extending an active interval or active mode according to an embodiment of the present disclosure;

FIG. 7 is a flow chart illustrating a method of transmitting and receiving data between an MTC terminal and a base station according to a first embodiment of the present disclosure;

FIG. 8 is a flow chart illustrating a method of transmitting and receiving data between an MTC terminal and a base station according to another variation of the first embodiment of the present disclosure;

FIG. 9 is a view illustrating an MTC operating parameter when an MTC terminal according to a second embodiment of the present disclosure is operated in an idle mode in a power saving mode;

FIG. 10 is a flow chart illustrating a method in which an MTC terminal according to a second embodiment of the present disclosure is operated in an idle mode in a power saving mode;

FIG. 11 is a flow chart illustrating a method in which an MTC terminal according to another variation of the second embodiment of the present disclosure is operated in an idle mode in a power saving mode;

FIG. 12 is a view illustrating the state diagram of an MTC terminal based on FIG. 11; and

FIG. 13 is an interval block diagram illustrating a terminal and a base station in a wireless access system to which an embodiment of the present disclosure is applicable.

The technology below will be used for various mobile communication systems such as CDMA (Code Division Multiple Access), FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), SC-FDMA (Single Carrier Frequency Division Multiple Access), or the like. CDMA can be implemented using a radio technology such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented using a radio technology such as GSM (Global System for Mobile communication)/GPRS (General Packet Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, E-UTRA (Evolved UTRA), or the like. IEEE 802.16m is an evolution of IEEE 802.16e, and provides backward compatibility to an IEEE 802.16e-based system.

Furthermore, IEEE 802.16p provides communication standard for supporting machine type communication (MTC).

UTRA is part of UMTS (Universal Mobile Telecommunication System). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution), as part of E-UMTS (Evolved UMTS) that uses Evolved-UMTS Terrestrial Radio Access (E-UTRA), employs OFDMA in the downlink and employs SC-FDMA in the uplink. LTE-A(LTE-Advanced) is an evolution of 3GPP LTE.

It should be noted that technological terms used herein are merely used to describe a specific embodiment, but not to limit the present invention. Also, unless particularly defined otherwise, technological terms used herein should be construed as a meaning that is generally understood by those having ordinary skill in the art to which the invention pertains, and should not be construed too broadly or too narrowly. Furthermore, if technological terms used herein are wrong terms unable to correctly express the spirit of the invention, then they should be replaced by technological terms that are properly understood by those skilled in the art. In addition, general terms used in this invention should be construed based on the definition of dictionary, or the context, and should not be construed too broadly or too narrowly.

Incidentally, unless clearly used otherwise, expressions in the singular number include a plural meaning. In this application, the terms "comprising" and "including" should not be construed to necessarily include all of the elements or steps disclosed herein, and should be construed not to include some of the elements or steps thereof, or should be construed to further include additional elements or steps.

The terms including an ordinal number such as first, second, etc. can be used to describe various elements, but the elements should not be limited by those terms. The terms are used merely for the purpose to distinguish an element from the other element. For example, a first element may be named to a second element, and similarly, a second element may be named to a first element without departing from the scope of right of the invention.

In case where an element is "connected" or "linked" to the other element, it may be directly connected or linked to the other element, but another element may be existed therebetween. On the contrary, in case where an element is "directly connected" or "directly linked" to another element, it should be understood that any other element is not existed therebetween.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar elements are designated with the same numeral references regardless of the numerals in the drawings and their redundant description will be omitted. In describing the present invention, moreover, the detailed description will be omitted when a specific description for publicly known technologies to which the invention pertains is judged to obscure the gist of the present invention. Also, it should be noted that the accompanying drawings are merely illustrated to easily explain the spirit of the invention, and therefore, they should not be construed to limit the spirit of the invention by the accompanying drawings. The spirit of the invention should be construed as being extended even to all changes, equivalents, and substitutes other than the accompanying drawings.

FIG. 2 is a conceptual view illustrating a wireless communication system to which an embodiment of the present disclosure is applicable. The wireless communication system may be widely disposed to provide various communication services such as voice, packet data.

Referring to FIG. 2, a wireless communication system may include a terminal (or mobile station (MS)) 10 and a base station (BS) 20. The terminal 10 may be fixed or have mobility, and may be also referred to as another term, such as user equipment (UE), user terminal (UT), subscriber station (SS), wireless device, advanced mobile station (AMS), and the like. Furthermore, the terminal 10 may include the concept of an MTC or M2M terminal.

The base station 20 typically refers to a fixed station for performing communication with the terminal 10, and may be also referred to as another term, such as NodeB, base transceiver system, access point, and the like. One or more cells may exist in one base station 20.

The wireless communication system may be an orthogonal frequency division multiplexing (OFDM)/orthogonal frequency division multiple access (OFDMA)-based system.

OFDM may use a plurality of orthogonal subcarriers. OFDM may use an orthogonal characteristic between inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT). The transmitter may perform IFFT to transmit data. The receiver may perform FFT to restore original data. The transmitter may use IFFT to combine multiple subcarriers with one another, and the receiver may use the corresponding FFT to separate multiple subcarriers from one another.

Hereinafter, a method of transmitting and receiving data between an MTC terminal and a network entity for power saving proposed by the present disclosure will be described in detail.

Here, the network entity may be a base station, for example. Accordingly, the base station will be described below as an example of the network entity.

FIG. 3 is a flow chart illustrating a method of transmitting and receiving data between an MTC terminal and a base station according to an embodiment of the present disclosure.

First, an MTC terminal receives an MTC operating parameter from a base station (S310).

The MTC operating parameter may include a first power saving interval for prohibiting access to the network entity, a first active interval for allowing access to the network entity, a second power saving interval, and a second active interval.

Furthermore, the second power saving interval and the second active interval may be located within the first active interval, and repeated within the first active interval.

The first power saving interval is an interval for prohibiting access to the MTC terminal and base station, and may be also referred to as a "forbidden time interval". Accordingly, the MTC terminal is unable to transmit and/or receive data to and/or from the base station during the first power saving interval, and does not exchange any signal with the base station.

Furthermore, the first active interval is an interval for allowing access to the MTC terminal and base station, and may be also referred to as a "grant time interval". Accordingly, the MTC terminal receives control messages from the base station during the first active interval and transmits and/or receives data to and/or from the base station.

In particular, the second power saving interval and the second active interval are repeated during the first active interval, and the MTC terminal may receive control messages transmitted from the base station through the second active interval or transmit and/or receive data to and/or from the base station.

Here, the MTC terminal may perform synchronization with the base station or receive system information or multicast/broadcast data from the base station during the second power saving interval other than the first power saving interval.

Furthermore, the second power saving interval may be shorter than the first power saving interval, and the second active interval may be shorter than the first active interval.

The power saving interval and the active interval proposed by the present disclosure will be described in detail with reference to FIG. 4 which will be described later.

Then, the MTC terminal transmits and receives data to and/or from the base station based on an MTC operating parameter received from the base station (S320).

FIG. 4 is a view illustrating a power saving interval and an active interval according to an embodiment of the present disclosure.

As illustrated in FIG. 4, two power saving intervals, namely, a first and a second power saving interval, and two active intervals, namely, a first and a second active interval are assigned to the MTC terminal from the base station. Here, the active interval is an interval capable of receiving control information and/or data received from the base station, and may be also referred to as a listening interval.

As illustrated in FIG. 4, the first power saving interval 410 and the second power saving interval 420 are repeated, and it is seen that at least one second power saving interval 430 and at least one second active interval 440 are repeated during the first active interval.

Furthermore, the first power saving interval may be longer than the second power saving interval, and the first active interval may be longer than the second active interval.

Fundamentally, the MTC terminal may be operated in a power saving mode during the power saving interval and the active interval. Here, the power saving mode refers to a state in which the power of the MTC terminal is turned off, or a mode in which the MTC terminal can receive basic system information or data transmitted via broadcast or multicast from the base station.

As illustrated in FIG. 4, subsequent to the completion of the first power saving interval, the second power saving interval and the second active interval are repeated during the first active interval.

The MTC terminal may perform synchronization with the base station during the second power saving interval or receive system information or broadcast and/or multicast traffic from the base station.

However, the MTC terminal cannot receive dedicated data during the second power saving interval. In other words, the MTC terminal cannot receive unicast data transmitted from the base station during the second power saving interval.

The MTC terminal may receive paging message or traffic indication message from the base station during the second active interval. Furthermore, the base station may transmit data directly to the MTC terminal during the second active interval without transmitting a traffic indication message to the MTC terminal.

Upon receiving a paging message, a traffic indication message or data during the second active interval, the MTC terminal switches from a power saving mode to an active mode.

As illustrated in FIGS. 7 through 11 which will be described later, the MTC terminal may be operated like in an idle mode or sleep mode in the power saving mode.

First, the MTC terminal receives a paging message from the base station during an active interval, particularly, during the second active interval when the power saving mode is operated in an idle mode, and the MTC terminal performs a network entry process to the base station when the received paging message calls the terminal itself. Then, the MTC terminal switches to a connected mode to transmit and/or receive data to and/or from the base station.

Furthermore, when the power saving mode is operated in a sleep mode, the MTC terminal may receive a traffic indication message from the base station during an active interval, particularly, the second active interval, or receive data directly from the base station without receiving the traffic indication message.

Subsequently, when the base station notifies the MTC terminal that data transmission is completed, the MTC terminal that has received it operates in a power saving mode again using a power saving mode related parameter that has been initially set.

Here, the first power saving interval may be set on the basis of a forbidden time interval or an interval value between two communication windows, which is set in a time-controlled traffic feature of the application level.

Furthermore, the first power saving interval may be determined by a network entity such as a base station or M2M server.

FIG. 5 is a flow chart illustrating the operation of an M2M terminal during a power saving interval and an active interval according to an embodiment of the present disclosure.

First, the MTC terminal receives an MTC operating parameter corresponding to the step S310 of FIG. 3 from the base station. The MTC operating parameter may be received through a network entry process between the MTC terminal and the base station or a deregistration process transmitted and received to allow the terminal to initially enter an idle mode in a connected mode. Furthermore, when a power saving mode procedure between the MTC terminal and the base station is separately defined, the MTC operating parameter may be received from the base station through a process in which the MTC terminal switches to a power saving mode. In other words, the MTC operating parameter may be received from the base station through a message transmitted and received through the power saving mode procedure.

Subsequently, the MTC terminal operates in a power saving mode during the first power saving interval, and operates in a power saving mode and/or active mode (or connected mode) during the first active interval (S510).

In other words, subsequent to the access to the base station, the MTC terminal basically maintains a power saving mode, and upon receiving data during the second active interval within the first active interval or receiving a traffic indication message or paging message notifying the occurrence of data from the base station (S520), the MTC terminal switches to (or enters) an active mode or connected mode from the power saving mode (S530).

Subsequently, the MTC terminal transmits and/or receives data to and/or from the base station in an active mode (S540).

Subsequently, upon receiving a mode change indicator indicating mode change or receiving a traffic completion indication message notifying that traffic occurrence is completed from the base station during the active mode (S550), the MTC terminal switches to (or enters) a power saving mode again from the active mode (S560). In other words, the MTC terminal operates in a power saving mode by reusing a parameter that has been applied to the power saving mode prior to the active mode, and it is periodically repeated according to whether data is transmitted and/or received to and/or from the base station.

FIG. 6 is a view illustrating a case of extending an active interval or active mode according to an embodiment of the present disclosure.

Referring to FIG. 6, when the MTC terminal is transmitting and/or receiving data to and/or from the base station in an active mode during the first active interval, and the data transmission and reception is not completed prior to the completion of the first active interval (S610), the MTC terminal maintains a current active mode until data transmission and reception with the base station is completed (S620). In other words, the MTC terminal performs an active mode even during the first power saving interval subsequent to the completion of the first active interval until data transmission and reception with the base station is completed. Accordingly, when data transmission and reception between the MTC terminal and the base station is not completed during the first active interval, it is seen that the first active interval is extended up to the completion of data transmission and reception or the active mode of the MTC terminal is extended up to the first power saving interval.

Subsequently, when data transmission and reception with the base station is completed (S630), the MTC terminal switches an active mode that has been maintained during the first power saving interval to a power saving mode (S640).

Here, the MTC terminal receives a mode change indicator or traffic indication message from the base station, thereby completing data transmission and reception with the base station.

Here, the MTC terminal transmits and/or receives UL data newly generated during the first power saving interval or DL data received through a backbone to and/or from the base station during the first active interval of the next cycle.

The description of extending the active interval or the active mode of the MTC terminal may be of course also applicable to embodiments (operating in an idle mode or sleep mode) which will be described later.

First embodiment

According to a first embodiment, there is provided a case where the power saving mode of the MTC terminal proposed by the present disclosure operates in a form similar to the sleep mode defined in an 802.16 system.

FIG. 7 is a flow chart illustrating a method of transmitting and receiving data between an MTC terminal and a base station according to a first embodiment of the present disclosure.

Referring to FIG. 7, the first and the second power saving interval correspond to a first sleep window (SW1) and a second sleep window (SW2), respectively, and the first and the second active interval correspond to a first listening window (LW1) and a second listening window (LW2), respectively.

In other words, the MTC terminal receives an MTC operating parameter including a first and a second sleep window and a first and a second listening window from the base station.

As illustrated in FIG. 7, the MTC terminal operates in a first sleep window and a first listening window in the power saving mode (or sleep mode) based on the received MTC operating parameter.

The MTC terminal operates in a power saving mode or sleep mode during the first sleep window. In other words, the MTC terminal may turn off power during the first sleep window.

Furthermore, the second sleep window and the second listening window are repeated within the first listening window, and the MTC terminal may receive data or a control message such as a traffic indication message notifying traffic occurrence from the base station during the second listening window.

Here, upon receiving data or a traffic indication message from the base station, the MTC terminal switches from a power saving mode (or sleep mode) to a normal mode.

Subsequently, upon receiving a mode change indicator or traffic completion indication message from the base station, the MTC terminal switches from the normal mode to the power saving mode again.

Here, the MTC terminal may operate in a power saving mode or sleep mode as in the first sleep window in the second sleep window. In other words, the MTC terminal may turn off power during the second sleep window.

FIG. 8 is a flow chart illustrating a method of transmitting and receiving data between an MTC terminal and a base station according to another variation of the first embodiment of the present disclosure.

As illustrated in FIG. 8, it is seen that the first listening window defined in FIG. 7 is expressed as an active duration, and the first sleep window is expressed as an inactive duration.

Second embodiment

According to a second embodiment, there is provided a case where the power saving mode of the MTC terminal proposed by the present disclosure operates in a form similar to the idle mode defined in an 802.16 system.

FIG. 9 is a view illustrating an MTC operating parameter when an MTC terminal according to a second embodiment of the present disclosure is operated in an idle mode in a power saving mode.

The base station assigns an MTC operating parameter including two paging parameter sets to the MTC terminal.

Here, the paging parameter set may include a paging cycle, a paging offset, a paging group ID, and a paging listening interval length.

A first paging parameter set included in the MTC operating parameter may be assigned as a long period of time based on time-controlled interval information exchanged between the MTC terminal and the base station. Here, the time-controlled interval information may include a grant time interval, a communication window, a forbidden time interval, and the like.

Furthermore, a second paging parameter set may be applicable within a paging listening interval included in the first paging parameter set, and may be assigned similarly to the existing HTC terminal based on a short period of time.

In other words, the fist paging parameter set may include paging cycle A, paging offset B, and paging interval C, and the second paging parameter set may include paging cycle D, paging offset E, and paging interval F.

As illustrated in FIG. 9, the MTC terminal operates in an unavailable interval during an interval other than the paging interval C.

Furthermore, the MTC terminal determines a substantial paging interval F based on paging cycle D and paging offset E within the paging interval C.

In other words, the MTC terminal determines paging interval F within the paging interval C as a substantial paging interval, and operates in an idle mode.

FIG. 10 is a flow chart illustrating a method in which an MTC terminal according to a second embodiment of the present disclosure is operated in an idle mode in a power saving mode.

As illustrated in FIG. 10, the base station transmits a paging message to the MTC terminal during the paging interval F (S1010).

When a paging message received from the base station during the paging interval F is a page corresponding to the terminal itself, the MTC terminal switches from an idle mode (or state) to an active mode (S1020).

Subsequently, the MTC terminal transmits and/or receives data to and/or the base station in an active mode (S1030).

Furthermore, when the MTC terminal completes data transmission and reception with the base station in an active mode (S1040), the MTC terminal operates in an idle mode again based on paging parameters that have been used prior to the active mode (S1050). Here, upon receiving a traffic completion indication message, a mode change indicator, or an indicator indicating last traffic from the base station, the MTC terminal completes data transmission and reception with the base station.

In other words, the base station may transmit a last PDU indicator (or mode change indicator) to notify data transmission complete to the MTC terminal.

FIG. 11 is a flow chart illustrating a method in which an MTC terminal according to another variation of the second embodiment of the present disclosure is operated in an idle mode in a power saving mode.

As illustrated in FIG. 11, it is seen that paging offset B and paging interval C during paging cycle A defined in FIG. 10 are expressed in the form of an inactive duration and an active duration, respectively, and paging offset E during paging cycle D is expressed as a paging unavailable interval.

FIG. 12 is a view illustrating the state diagram of an MTC terminal based on FIG. 11.

As illustrated in FIG. 12, the MTC terminal may largely operate in three states. In other words, the MTC terminal may perform power saving through M-initialization 1210, an active state 1220, and an inactive state 1230.

Furthermore, the MTC terminal may operate in two modes (M-normal 1222, M-idle 1221) in the active state, and operate in an M-DCR mode in the inactive state.

First, when power is turned on, the MTC terminal maintains an initialization state.

Subsequently, the MTC terminal performs an initial network entry process with the base station to maintain an active state (S1210). When the MTC terminal performs a deregistration procedure with the base station in the active state or turns off power, the MTC terminal returns to an initialization state again (S1220).

The initial network entry process may include a process of synchronizing with the base station, a process of performing ranging, a process of performing capability negotiation, a process of performing an authentication procedure, an process of performing a registration procedure, and the like.

The MTC terminal may exchange a MTC operating parameter to be used in an idle mode with the base station through the initial network entry process, particularly, a network registration process.

In other words, the MTC terminal may exchange a first power saving interval, a first active interval information, and a second power saving interval and a second active interval information applied in an idle mode of the first active interval with the base station through an initial network process with the base station. The second power saving interval and the second active interval information may be parameters such as paging offset, paging, cycle, paging interval, and the like.

Subsequently, the MTC terminal operates in an M-idle mode for power saving in an active state.

Here, when the MTC terminal in an M-idle mode receives a paging message (or traffic indication message) from the base station or has a packet to be transmitted to the base station, the terminal switches to an M-normal mode (S1230). Furthermore, when the MTC terminal receives a request to M-idle from the base station or requests M-idle to the base station or data transmission and reception with the base station is all completed though the active duration is not completed in an M-normal mode, the MTC terminal may operate in an M-idle mode again (S1240). Here, the active duration continues until the completion.

When the MTC terminal in an M-normal mode completes all data transmission and reception with the base station and active duration is also completed or when the MTC terminal requests a switch to an M-DCR mode or receives a request to an M-DCR mode, the MTC terminal maintains an inactive state. In other words, the MTC terminal switches from an M-normal mode to an M-DCR mode (S1250).

Here, the M-DCR mode may be distinguished from the M-idle mode. In other words, the MTC terminal may perform synchronization with the base station or receive system information or the like from the base station in an M-idle mode, whereas the MTC terminal does not transmit and/or receive any signal to and/or from the base station since access to the base station is prohibited in the M-DCR mode, and also the MTC terminal is not required to monitor DL signals.

Furthermore, the MTC terminal switches from an M-DCR mode to an M-idle mode when inactive duration is completed during the operation to the M-DCR mode (S1260). On the contrary, when active duration is completed, the MTC terminal in an M-idle mode switches to an M-DCR mode (S1270).

The above-described embodiments and modification examples may be combined with one another. Accordingly, each embodiment may not be implemented as a single but implemented in combination with one another when the need arises. Such combinations can be easily implemented by those skilled in the art reading this specification and the combinations thereof will not be described below in detail. However, even if not described, it should be understood that the combinations thereof will not be excluded from the present invention, and still fall within the scope of the present invention.

The foregoing embodiments and modification examples may be implemented through various means. For example, the embodiments of the present disclosure may be implemented by hardware, firmware, software, or any combination thereof.

In case of a hardware implementation, a method according to the embodiments of the present disclosure may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or the like.

In case of a firmware or software implementation, a method according to the embodiments of the present disclosure may be implemented in the form of a module, procedure, function, or the like, which performs the functions or operations as described above. The software codes may be stored in a memory unit to be driven by a processor. The memory unit may be located at an inner or outer portion of the processor to send and/or receive data to and/or from the processor by various publicly-known means.

For example, the method according to the present invention as described above may be implemented by software, hardware, or a combination of both. For example, the method according to the present invention may be stored in a storage medium (for example, internal memory, flash memory, hard disk, and so on), and may be implemented through codes or instructions in a software program that can be performed by a processor (for example, internal microprocessor). It will be described with reference to FIG. 13.

A terminal 10 may include a controller 11, a memory 12, and a radio frequency (RF) unit 13.

Furthermore, the terminal may also include a display unit, a user interface unit, and the like.

The controller 11 implements the proposed functions, processes and/or methods. The layers of the radio interface protocol may be implemented by the controller 11.

The memory 12, which is connected to the controller 11, may store protocols or parameters for performing wireless communication. In other words, the memory 12 may store terminal-driving systems, applications, and general files.

The RF unit 13, which is connected to the controller 11, may transmit and receive radio signals.

In addition, the display unit may display various information of the terminal, and well-known elements such as a liquid crystal display (LCD), organic light emitting diodes (OLED), or the like may be used. The user interface unit may be implemented in combination of well-known user interfaces such as a keypad, a touch screen, or the like.

A base station 20 may include a controller 21, a memory 22, and a radio frequency (RF) unit 23.

The controller 21 implements the proposed functions, processes and/or methods. The layers of the radio interface protocol may be implemented by the controller 21.

The memory 22, which is connected to the controller 21, may store protocols or parameters for performing wireless communication.

The RF unit 23, which is connected to the controller 21, may transmit and receive radio signals.

The

controller

11, 21 may include application-specific integrated circuits (ASICs), other chip sets, logic circuit and/or data processing devices. The

memory

12, 22 may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and/or other storage devices. The

RF unit

13, 23 may include a baseband circuit for processing radio signals. When the embodiment is implemented by software, the foregoing technique may be implemented by a module (process, function, etc.) performing the foregoing function. The module may be stored in the

memory

12, 22, and implemented by the

controller

11, 21.

The

memory

12, 22 may be located inside or outside the

controller

11, 21, and may be connected to the controller, 11, 21 through well-known various means.

Claims

A method of an MTC (machine type communication) terminal to transceive data with a network entity in a wireless access system supporting MTC, the method comprising:

receiving an MTC operating parameter from the network entity; and

transceiving data with the network entity based on the received MTC operating parameter, wherein the MTC operating parameter comprises:

a first power saving interval for prohibiting access to the network entity, a first active interval for allowing access to the network entity, a second power saving interval, and a second active interval, and

the second power saving interval and the second active interval are located within the first active interval, and repeated within the first active interval.
The method of claim 1, wherein said transceiving data comprises:

performing a network re(entry) process with the network entity, and then operating in a power saving mode;

receiving first indication information or data indicating that traffic occurs during the second active interval from the network entity;

switching from the power saving mode to an active mode, and

transmitting and/or receiving data to and/or from the network entity in the active mode.
The method of claim 2, further comprising:

extending the first active interval or maintaining an active mode during the first power saving interval when data transmission and reception with the network entity is not completed at the completion timing of the first active interval.
The method of claim 2 or 3, further comprising:

receiving second indication information indicating that traffic occurrence is completed or a mode change indicator indicating mode change from the network entity; and

switching from the active mode to the power saving mode.
The method of claim 2, wherein when the power saving mode is a sleep mode supported in an 802.16 system,

the first and the second power saving interval correspond to a first sleep window (SW1) and a second sleep window (SW2), respectively, and

the first and the second active interval correspond to a first listening window (LW1) and a second listening window (LW2), respectively.
The method of claim 2, wherein when the power saving mode is a idle mode supported in an 802.16 system,

the first and the second power saving interval correspond to a first unavailable interval (UAI1) and a second unavailable interval (UAI2), respectively, and

the first and the second active interval correspond to a first available interval (AI1) and a second available interval (AI2), respectively.
The method of claim 2, wherein the MTC operating parameter is received through the network re(entry) process.
The method of claim 1, wherein the MTC terminal has a time-controlled traffic feature.
The method of claim 1, wherein data transceived with the network entity during the first active interval is unicast data.
The method of claim 1, wherein the power saving mode is a mode for turning off the power of the MTC terminal or exchanging basic information with the network entity.
The method of claim 1, wherein the basic information is information required for the M2M terminal to perform synchronization with the network entity, system information, multicast/broadcast data, or a downlink (DL) signal.
A terminal for transceiving data with a network entity in a wireless access system supporting machine type communication (MTC), the terminal comprising:

a wireless communication unit configured to transceive radio signals to and/or from the outside; and

a controller connected to the wireless communication unit,

wherein the controller controls the wireless communication unit to receive an MTC operating parameter from the network entity, and controls the wireless communication unit to transceive data to and/or from the network entity based on the received MTC operating parameter, and the MTC operating parameter comprises:

a first power saving interval for prohibiting access to the network entity, a first active interval for allowing access to the network entity, a second power saving interval, and a second active interval, and

the second power saving interval and the second active interval are located within the first active interval, and repeated within the first active interval.
The terminal of claim 12, wherein the controller controls the wireless communication unit to receive first indication information or data indicating that traffic occurs during the second active interval in a power saving mode from the network entity, and controls the wireless communication unit to switch from the power saving mode to an active mode, and transmit and/or receive data to and/or from the network entity in the active mode.
The terminal of claim 13, wherein the controller controls to extend the first active interval or maintain an active mode during the first power saving interval when data transmission and reception with the network entity is not completed at the completion timing of the first active interval.
The terminal of claim 13 or 14, wherein the controller controls the wireless communication unit to receive second indication information indicating that traffic occurrence is completed or a mode change indicator indicating mode change from the network entity, and controls to switch from the active mode to the power saving mode.
The terminal of claim 12, wherein the terminal has a time-controlled traffic feature.