Device to device discovery method for user equipment and network entity and user equipment and network entity using the same

A user equipment (UE) comprising:

• a wireless transmitter for transmitting wireless data;
• a wireless receiver for transmitting wireless data;
• a processing circuit coupled to the wireless transmitter and the wireless receiver and is configured for:
• initiating a D2D discovery process with a window value, wherein the window value stands for a time window and is a positive number;
• transmitting, by using the transmitter, a first proximity discovery request comprising the window value;
• detecting a cancellation event to cancel the D2D discovery process in response to transmitting the first proximity discovery request;
• stopping the D2D discovery process if the window value decreases to a specific threshold in response to detecting the cancellation event;
• and
• transmitting, by using the transmitter, a cancel proximity discovery request to cancel the D2D discovery process in response to receiving the cancellation event and if another proximity discovery request does not exist within the UE.

A device to device (D2D) discovery method applicable to a network entity comprising:

• receiving a first proximity discovery request comprising a first window value executed onto execute a network assisted D2D discovery process, wherein the first window value is a non-negative number;
• performing a proximity estimation and a user equipment (UE) status estimation in response to receiving the proximity discovery request;
• cancelling the network assisted D2D discovery process in response to performing the proximity estimation and the UE status estimation, wherein cancelling the network assisted D2D discovery process comprises:
• transmitting a cancel proximity discovery request;
• and
• transmitting a cancel location reporting request.

A network entity comprising:

• a transmitter for transmitting data;
• a receiver for receiving data;
• a processing circuit coupled to the transmitter and the receiver and is configured for:
• receiving through the receiver a first cancel proximity request comprising a network level discoverer identifier (ID), an application ID, and an application layer discoveree ID;
• transmitting through the transmitter a second cancel proximity request comprising the network level discoverer ID and a network level discoveree ID in response to receiving the first cancel proximity request;
• receiving through the receiver a first acknowledgement signal that corresponds to the second cancel proximity request in response to transmitting the second cancel proximity request;
• and transmitting through the transmitter a second acknowledgement signal that corresponds to the first cancel proximity request in response to receiving the first acknowledgement signal.

A device to device (D2D) discovery method applicable to a network entity comprising:

• receiving a first cancel proximity request comprising a network level discoverer identifier (ID), an application ID, and an application layer discoveree ID;
• transmitting a second cancel proximity request comprising the network level discoverer ID and a network level discoveree ID in response to receiving the first cancel proximity request;
• receiving a first acknowledgement signal that corresponds to the second cancel proximity request in response to transmitting the second cancel proximity request;
• and
• transmitting a second acknowledgement signal that corresponds to the first cancel proximity request in response to receiving the first acknowledgement signal.