TWI549534B - A method of message retransmission and user equipment using the same - Google Patents

Description

Method for retransmitting a message and user equipment using the same

The present invention relates to a proximity service (ProSe) technology, and more particularly to a method for message retransmission for a proximity service discovery procedure and a user equipment using the method.

In recent years, with the rapid development of mobile communication technologies and smart handheld devices, global mobile broadband users and mobile data traffic have also grown exponentially. However, the explosion of mobile broadband users and data traffic has caused problems in spectrum, frequency utilization and network coverage for mobile communication networks. Therefore, in the next generation (Third Generation (4G), fifth generation (5G)) wireless communication technology of the Third Generation Partnership Project (3GPP), the above problems are solved. Program and technology discussion, in which device-to-device (D2D) communication technology is one of the key technologies.

In traditional mobile communication networks, user equipment (UE) such as smart phones and tablets need to pass through the core network. Transmit voice and data signals. The D2D technology uses the proximity device to discover and direct communication without transferring data through the core network to achieve offload, location-based service (LBS), etc. The result is an innovative business value for the operator.

The invention provides a method for message retransmission and a user equipment using the same, in the proximity service discovery program, by starting an additional timer, and not retransmitting the message before the timer expires, to avoid retransmission Too many messages.

The invention provides a method for message retransmission, which is suitable for a user equipment to perform a proximity service discovery procedure, and the method comprises the following steps. The first timer is started in response to transmitting a first message requesting authorization for the proximity service. If the second message in response to the first message is not received when the first timer expires, the second timer is started, wherein the first message is not transmitted until the second timer expires.

The present invention provides a user equipment suitable for performing a proximity service discovery procedure. The user equipment includes a transceiver and a processor. The transceiver is used to transmit and receive wireless signals. The processor is coupled to the receiver and is configured to perform the following steps. The first message for the authorization request for the proximity service is transmitted through the transceiver and the first timer is started. If the second message in response to the first message is not received by the transceiver when the first timer expires, the second timer is started. The first message is not transmitted through the transceiver until the second timer expires.

Based on the above, if the processor of the embodiment of the present invention does not receive the second message in response to the first message when the first timer expires, the second timer is started, and the second timer is not heavy until the second timer expires. Pass the first message. Thereby, the user equipment can reduce the number of retransmissions per unit time, thereby reducing the power consumption of the user equipment and reducing the network load.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧Communication system

120‧‧‧Base station

110, 110a, 110b‧‧‧ User equipment

131‧‧‧Mobility management entity

130‧‧‧core network

135‧‧‧Proximity service function

133‧‧‧Home User Server

137‧‧‧ service gateway

139‧‧‧ Packet Information Network Gateway

S310~S330, S410~S470‧‧‧ steps

1 is a schematic diagram of a communication system in accordance with an embodiment of the invention.

2 is a block diagram showing a user equipment in accordance with an embodiment of the present invention.

FIG. 3 is a flow chart illustrating a method for message retransmission according to an embodiment of the invention.

4 is a flow chart showing the interaction between a user equipment and a proximity service function in an announcement requesting program in accordance with an embodiment of the present invention.

In a wireless communication protocol, a user device transmits a service request to a service provider and the service provider responds to the service request, which is a common hand shaking procedure. If the user equipment does not receive a response to the service request, the service request is usually re-transmitted. Accordingly, in order to reduce the power consumption of the user equipment In the proximity of the proxies (ProSe) discovery program (for example, an announce request procedure), the embodiment of the present invention proposes two timers, the first timer is started. Is the first message (for example, DISCOVERY_REQUEST) that is used to transmit the authorization request for ProSe, and the activation of the second timer is a response that does not receive the first message when the first timer expires. (For example, DISCOVERY_RESPONSE), and the first message is not retransmitted until the second timer expires. Thereby, the user equipment reduces the number of times the first message is retransmitted, thereby reducing power consumption and signaling traffic load. A plurality of embodiments in accordance with the spirit of the present invention are set forth below, and those applying the present embodiment can be appropriately adjusted according to their needs, and are not limited to the contents described in the following description.

1 is a schematic diagram of a communication system in accordance with an embodiment of the invention. Referring to FIG. 1, the communication system 100 includes a user equipment 110, a base station 120, and a core network 130. It should be noted that, in FIG. 1, only two user equipments 110a, 110b and one base station 120 are taken as an example, but not limited thereto.

User device 110 may represent various embodiments, which may include, but are not limited to, a mobile station, an advanced mobile station (AMS), a server, a client, a desktop computer, a notebook computer, a network Computer, workstation, personal digital assistant (PDA), personal computer (PC), scanner, telephone device, pager, camera, television, handheld video game device, music device, wireless Sensors, etc.

2 is a block diagram illustrating user equipment 110 in accordance with an embodiment of the present invention. The user device 110 can be represented at least by the functional elements as illustrated in FIG. The user equipment 110 can include at least, but not limited to, a transceiver 113, an analog to digital (A/D)/digital to analog (D/A) converter 114, a processor 116, optionally a storage unit 115, and a Or a plurality of antenna units 112. The transceiver 113 wirelessly transmits a downlink signal and receives an uplink signal. Transceiver 113 can also perform operations such as low noise amplification, impedance matching, mixing, upconversion or down conversion, filtering, amplification, and the like. Analog to digital (A/D)/digital to analog (D/A) converter 304 is configured to convert from analog signal format to digital signal format during uplink signal processing, and during downlink signal processing The digital signal format is converted to an analog signal format.

Processor 116 is configured to process digital signals and to execute a program (e.g., a ProSe finder) in accordance with an illustrative embodiment of the present invention. In addition, the processor 116 can be coupled to the storage unit 115 to store code, device configuration, codebook, buffered or permanent data, and can also record multiple modules executable by the processor 116. The function of the processor 116 can be achieved by using a programmable unit such as a microprocessor, a microcontroller, a digital signal processing (DSP) chip, or a Field Programmable Gate Array (FPGA). To implement. The function of the processor 116 can also be implemented by a separate electronic device or an integrated circuit (IC), and the processor 116 can also be implemented by hardware or software.

In addition, the user equipment 110 of the embodiment of the present invention is a ProSe-enabled electronic device, that is, the user equipment 110 can perform, for example, It is a function of exchanging ProSe control information, opening a ProSe Direct Discovery program with other proximity service enabled user devices, and performing ProSe direct communication.

The base station 120 can be represented in various embodiments, which can include, for example, but not limited to, an evolved Node B (eNB), a home evolved Node B (HeNB), and an advanced base station (ABS). Base transceiver system (BTS), access point, home base station, relay, scatterer, repeater, intermediate node, intermediate and/or Or a satellite-based communication base station.

The core network 130 can be an Evolved Packet Core (EPC) network or other core network of third generation (3G), fourth generation (4G) or even fifth generation (5G) communication technologies. The core network 130 may include at least, but not limited to, a Mobility Management Entity (MME) 131, a Home Subscriber Server (HSS) 133, a ProSe function 135, and a service gateway. (Serving Gateway; S-GW) 137 and Packet Data Network Gateway (PDN-GW).

FIG. 3 is a flow chart illustrating a method for message retransmission according to an embodiment of the invention. Referring to FIG. 3, the method of this embodiment is applicable to the communication system 100 of FIG. 1 and the user equipment 110 of FIG. Hereinafter, the method described in the embodiments of the present invention will be described in conjunction with various elements in the communication system 100 and the user equipment 110. The various processes of the method can be adjusted accordingly according to the implementation situation, and are not limited thereto.

In step S310, the processor 116 transmits a first message for the authorization request of the proximity service through the transceiver 113, and starts the first timer. Specifically, in the ProSe direct discovery program, after receiving the request from the upper layer (for example, the ProSe application) for announcement, the user equipment 110 performs an announcement request procedure to obtain for enabling with other proximity services. The ProSe Application Code is announced on the interface between the user devices (for example, the PC5 interface between the user devices 110a and 110b). At this time, the user equipment 110 transmits a first message such as a DISCOVERY_REQUEST to the ProSe function 135 (for example, through the PC3 interface) to obtain a registered public land mobile network (PLMN). Authorization. The first message includes, for example, a ProSe Application identification (ID), a transaction ID, a command set to "announce", and a user equipment identifier. (UE identity) and other information.

Further, in response to the transmission of the first message, the processor 116 initiates a first timer (eg, T3901). The timer value of this timer is, for example, 30 seconds, 40 seconds, or 60 seconds.

It should be noted that the signaling path between the user equipment 110 and the ProSe function 135 may pass through one or more network entities (for example, the MME 131, the HSS 133, etc.), and the embodiment of the present invention does not limit the foregoing transmission path or method. .

Then, in step S330, if the second message in response to the first message is not received through the transceiver 113 when the first timer expires, the second timing is started. Device. The first message is not retransmitted through the transceiver 113 until the second timer expires. Specifically, the base station 120 and the core network 130 may have any network problem or a problem with the connection between the user equipment 110, which may cause the user equipment 110 not to receive the response to the first message. The second message (for example, DISCOVERY_RESPONSE). Since these network or connection problems may not return to normal immediately, if the first message is retransmitted immediately after the first timer expires, it may not be possible to receive the second message before the first timer expires. In this way, the first message is continuously retransmitted in a short time, which may result in improper consumption of battery power and burden of signaling traffic. Accordingly, the embodiment of the present invention additionally activates a second timer (eg, T3902) to cause the user equipment to no longer transmit the first signal until the second timer expires. In an embodiment, the user equipment 110 can wait until the network or connection problem returns to normal and the second timer expires, then retransmit the announcement request procedure by transmitting the first message through the transceiver 113, and then restart the first a timer.

In another embodiment, before the expiration of the second timer, the processor 116 further closes the existing secure connection with the ProSe function 135 via the transceiver 113. Therefore, during this time, the transceiver 113 does not receive or respond to the second message replied by the ProSe function 135. When the second timer expires, the processor 116 establishes a new secure connection with the ProSe function 135 through the transceiver 113 to retransmit the first message.

In other embodiments, the processor 116 further multiplies the timing value of the second timer by a multiple value (eg, 2, 3, or 5, etc.). The aforementioned network or connection problem may pass through the first timer and the second timer, and still cannot be restored to a normal state. In this situation The user device 110 may still be unable to receive the second message. Accordingly, upon expiration of the next first timer, the processor 116 extends the timing value of the second timer by a multiple to allow the user device 110 to extend the time to wait for the problem to resume. In some embodiments, the second timer has a timing maximum (eg, 30 minutes, 40 minutes, etc.). If the timing value of the second timer is greater than the timing maximum value, the processor 116 sets the timing value of the second timer to the timing maximum value.

For example, the initial timer value of the first timer and the second timer is 1 minute, and when the second timer expires, if the user equipment 110 has not received the second message, the processor 116 The timing value of the second timer is set to 2 minutes, and the second timer is started. The expiration of the second timer is extended by the expiration of the third and fourth first timers and thereafter. Assume that the maximum value of the timer is 30 minutes. If the timing value of the second timer is also 30 minutes, then the next time the first timer expires, the processor 116 still sets the timing value of the second timer. It is 30 minutes. In this way, in addition to prolonging the waiting time, it is also possible to avoid excessive waiting time and make the user feel inconvenient.

It should be noted that, in other embodiments, if the user equipment 110 receives the second message after the first timer is started and before the first timer expires, the processor 116 stops the first timer. Also, the processor 116 does not initiate the subsequent second timer.

To assist in understanding the embodiments of the present invention, an exemplary request procedure between the user equipment 110 and the ProSe function 135 will be described below.

4 is a user equipment in an announcement requesting program according to an embodiment of the present invention Flowchart of interaction between 110 and ProSe function 135. Referring to FIG. 4, in step S410, the user equipment 110 starts the first timer and transmits a search request (DISCOVERY_REQUEST) to the ProSe function 135. Assume that the first timer has a timing value of 30 seconds. If the discovery response (DISCOVERY_RESPONSE) transmission from the ProSe function 135 fails (step S440), the ProSe function 135 cannot receive the DISCOVERY_REQUEST, or the ProSe function 135 cannot transmit the DISCOVERY_RESPONSE, the processor 116 waits until the first timer expires. The second timer (step S460), but does not transmit DISCOVERY_REQUEST through the transceiver 113. Assume that the timing value of the second timer is one minute. When the processor 116 waits until the first timer expires (i.e., one minute later), the first timer is started again, and the DISCOVERY_REQUEST is transmitted through the transceiver 113 (step S470).

In the present invention, keywords or terms of the 3GPP class are used merely as examples to present inventive concepts in accordance with the present invention; however, the same concepts presented in the present invention can be applied to any other system, such as IEEE, as generally known to those skilled in the art. 802.11, IEEE 802.16, WiMAX, and the like.

In summary, the user equipment of the embodiment of the present invention starts the second timer in addition to the authorization request for ProSe, and starts the second timer when the first timer expires, and is in the second The first message is not retransmitted until the timer expires. Thereby, the battery consumption of the user equipment can be effectively saved and the network traffic load can be reduced.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art without departing from the invention. In the spirit and scope, the scope of protection of the present invention is subject to the definition of the appended patent application.

S310~S330‧‧‧Steps

Claims (10)

A method for message retransmission is applicable to a user equipment performing a proximity service (ProSe) discovery process, the method comprising: responding to transmitting a first message for an authorization request of the proximity service, Activating a first timer; and if a second message responsive to the first message is not received when the first timer expires, a second timer is started, wherein the second timer is The first message will not be transmitted before the period. The method of claim 1, wherein the step of starting the second timer further comprises: transmitting the first message when the second timer expires, and starting the first timer. The method of claim 2, wherein the transmitting the first message and starting the first timer further comprises: multiplying the timing value of the second timer by a multiple value. The method of claim 3, further comprising: if the timing value of the second timer is greater than a timing maximum value, setting the timing value of the second timer to the timing maximum value. The method of claim 1, wherein the step of expiring the first timer further comprises: closing a secure connection with the proximity service function. A user equipment is adapted to perform a proximity service discovery procedure, the user equipment comprising: a transceiver for transmitting and receiving wireless signals; a processor coupled to the transceiver, the processor configured to perform Transmitting, by the transceiver, a first message for an authorization request for the proximity service, and initiating a first timer; and if the first timer expires, the response is not received through the transceiver A second message of the first message initiates a second timer, wherein the first message is not transmitted through the transceiver before the second timer expires. The user equipment of claim 6, wherein when the second timer expires, the first message is transmitted through the transceiver, and the processor starts the first timer. The user equipment of claim 7, wherein the processor multiplies the timing value of the second timer by a multiple of the value. The user equipment of claim 8, wherein if the timing value of the second timer is greater than a timing maximum value, the processor sets the timing value of the second timer to be the maximum timing. value. The user equipment of claim 6, wherein the processor is configured to close a secure connection with the proximity service function through the transceiver.