CLIAMS:CLAIMS
We claim:

1. A method of providing paging optimization in LTE devices, the method comprising:
establishing, by a first User Equipment (UE1), a Device-to-Device (D2D) communication with a second User Equipment (UE2);
sharing, by the second UE, a paging information with the first UE;
receiving, by a first UE, a paging message from the network;
sending a paging notification to the second UE on receiving a paging message for the second UE; and
establishing, by the second UE, an Radio Resource Control (RRC) connection with the network on receiving the paging notification from the first UE.

2. The method of claim 1, wherein the paging information associated with the second UE comprises of:
a paging occasion;
a Temporary Mobile Subscriber Identity (S-TMSI); and
a Tracking Area (TA) list.

3. The method of claim 1, wherein the first UE notifies reception of the paging message to the second UE by changing a coding scheme in the D2D communication.

4. The method of claim 1, wherein the first UE compares the S-TMSI in the paging message from the network to determine if the paging message is for the first UE or the second UE.

5. The method of claim 1, wherein the first UE is a paging monitoring device.
6. The method of claim 1, wherein the first UE is of a high battery power.

7. The method of claim 1, further comprising:
updating, by one of the first UE and the second UE, the TA list if at least one of the first UE and the second UE shifts to a different network area.

8. A wireless network system, comprising:
a LTE-based network;
a first User Equipment (UE1) in communication with the LTE based network; and
a second User Equipment (UE2) in a Device to Device (D2D) communication with the first UE;
wherein the first UE is adapted to:
monitor a paging message for the first and second UE from the LTE network; and
sending a paging notification to the second UE on receiving a paging message for the second UE from the LTE network.

9. The wireless network system of claim 7, wherein the second UE is adapted to establish an RRC connection with the LTE network on receiving the paging notification from the first UE.

10. The wireless network system of claim 7, wherein the second UE is adapted to monitor the D2D communication with the first UE.

Dated this the 02nd day of March 2015

Signature

KEERTHI J S
Patent agent
Agent for the applicant
,TagSPECI:

FORM 2

THE PATENTS ACT, 1970
[39 of 1970]
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(Section 10; Rule 13)

A METHOD FOR PAGING RECEPTION OPTIMIZATION IN LTE DIRECT DEVICES

SAMSUNG R&D INSTITUTE INDIA – BANGALORE PRIVATE LIMITED
# 2870, ORION Building, Bagmane Constellation Business Park,
Outer Ring Road, Doddanakundi Circle,
Marathahalli Post, Bangalore-560 037
An Indian company

The following specification particularly describes the invention and manner in which it is to be performed

FIELD OF THE INVENTION
The present invention relates to Device to Device (D2D) communication in Long Term Evolution (LTE) devices and more particularly relates to a method of paging reception optimization in LTE direct devices.

BACKGROUND OF THE INVENTION
A wireless system enables communications between two or more wireless entities such as fixed or mobile communication devices, base stations, servers and/or other devices capable of wireless communication. A wireless communication device is provided with an appropriate signal receiving and transmitting arrangement for enabling communication of voice and data. A wireless communication device is often referred to as user equipment (UE) or terminal.

A feature of the wireless system is paging for wireless devices. In accordance with the 3rd Generation Partnership Project (3GPP) protocol specification a base station site, referred to as an enhanced Node B (eNB) broadcasts paging parameters including paging cycle and information for use in calculation of paging occasions via system information (SI) signaling. After a communication device receives the information, it calculates corresponding paging frame (PF) and paging occasion (PO), based on its user equipment identity (UE ID) and the received parameters according to a predefined rule. When a paging message originates from the core network, the eNB calculates the paging frame and paging occasion in the same way and delivers the paging message in these slots so that the communication device is able to detect the message.

In the existing art, techniques to conserve battery life in mobile devices become increasingly important as mobile device use expands. The battery life is one of the most salient contributors to overall product experience. Even so, battery components are typically the largest and heaviest components of a mobile device.

All the UE’s monitor both the network paging and direct paging (D2D communication) for itself thereby draining battery power at both UE’s. Therefore, there exists a need for providing a method and system for paging reception optimization in LTE direct devices to reduce power consumption.

The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.

SUMMARY OF THE INVENTION
The various embodiments of the present invention disclose a method for paging reception optimization in LTE direct devices to reduce power consumption by either of the user equipment in direct communication. According to the present invention, the method of providing paging optimization in LTE devices is disclosed. The method includes the steps of establishing by a first user equipment (UE1), a Device-to-Device (D2D) communication with a second user equipment (UE2), sharing paging information with the first UE by second UE, receiving by a first UE, a paging message from the network, sending a paging notification to the second UE on receiving a paging message for the second UE, and establishing by the second UE, an Radio Resource Control (RRC) connection with the network on receiving the paging notification from the first UE.

According to an embodiment herein, the paging information associated with the second UE comprises of a paging occasion, a Temporary Mobile Subscriber Identity (S-TMSI), and a Tracking Area (TA) list.

According to an embodiment herein, the first UE notifies reception of the paging message to the second UE by changing a coding scheme in the D2D communication. The first UE compares the S-TMSI in the paging message from the network to determine if the paging message is for the first UE or the second UE.

According to an embodiment herein, the first UE is a paging monitoring device and is of a high battery power. Further both the UEs update the TA list if at least one of the first UE and the second UE shifts to a different network area and they exchange the change of TA list with each other.

In another aspect of the present invention, the wireless network system is disclosed. The system includes a LTE-based network, a first user equipment (UE1) in communication with the LTE based network, and a second user equipment (UE2) in a Device to Device (D2D) communication with the first UE, wherein the first UE is adapted to monitor a paging message for the first and second UE from the LTE network, and sending a paging notification to the second UE on receiving a paging message for the second UE from the LTE network.

According to an embodiment herein, the D2D communication can be enabled on any type of network comprising, but not limited to, WiFi, Bluetooth, ZigBee, NFC, WiMAX, LTE, HSPA, EV-DO and the like.

These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS
The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:

Figure 1 is a schematic representation illustrating LTE paging mechanism, according to the prior art illustration.

Figure 2 is a schematic representation illustrating Prose service (Lte Direct) architecture, according to the prior art illustration.

Figure 3 is a schematic representation illustrating direct paging pattern detection using the expression codes, according to an embodiment of the present invention.

Figure 4 is a schematic representation illustrating paging monitoring setup procedure in LTE Direct devices, according to an embodiment of the present invention.

Although specific features of the present invention are shown in some drawings and not in others, this is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method for paging reception optimization in lte direct devices to reduce power consumption by either of the user equipment in direct communication. In the following detailed description of the embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

Figure 1 is a schematic representation illustrating LTE paging mechanism. Paging in idle mode is a procedure to transmit paging message to the User Equipment (UE). Paging message is triggered either by MME in core network or eNB in Universal Terrestrial Radio Access Network (UTRAN). The paging procedure could be initiated from the network to inform to the UE through the paging message about the Incoming call/Incoming SMS from CS domain or PS domain, change of BCCH information, releasing the RRC connection or Earthquake and Tsunami Warning Service (ETWS) information.

The core network originated paging message is for informing the UE about Incoming Call or Incoming SMS either from CS or PS Domain. UTRAN originated paging message is for informing the UE about the change of BCCH information, releasing the RRC connection or ETWS information. In LTE, the UE needs to monitor Physical Downlink Control Channel (PDCCH) continuously to listen to paging message and this drains UE battery power heavily. Instead, if the UE is allowed to monitor PDCCH at predetermined period say every 60ms or 100ms, it will reduce UE’s power consumption. The process of monitoring PDCCH discontinuously to listen to paging message during idle state is known as Discontinuous Reception (DRX). The UEs in idle mode monitor the PDCCH channel for Paging - Radio Network Temporary Identifier (P-RNTI) used for paging to receive paging message from eNB. The UE needs to monitor the PDCCH only at certain UE specific paging occasion, i.e. only at specific sub-frame in specific radio frame and these paging occasions are configured by the Base Station (BS or eNB). The UE automatically wakes up during paging occasion to check if there is any paging intended for that UE and during other times the UE goes to sleep mode to save battery power.

Further, the paging frame and paging occasion for an UE in receiving paging messages is explained. Paging Frame (PF) is a Radio Frame in which the UE is looking for paging message and one paging frame may contain one or multiple paging occasions. Whereas, Paging Occasion (PO) is a sub-frame where there may be P-RNTI transmitted on PDCCH addressing the paging message for the UE. There is always only one paging occasion for each UE in a DRX cycle. To find out paging frame and paging occasion, the UE uses DRX parameters broadcasted in the system information SIB2.

Paging Frame and Paging Occupation Calculation

Paging Frame is given by following equation:
SFN mod T= (T div N)*(UE_ID mod N)
N: min (T, nB)

Index i_s pointing to Paging Occasion will be derived from following calculation:
i_s = floor (UE_ID/N) mod Ns
Ns = max (1, nB/T), which means that Ns is the larger value between 1 and NB/T.

Example:
Parameters broadcasted in SIB2:
Default Paging cycle=T; (value=rf128)
nB= Broadcasted in SIB2 (value=1T)

Paging Frame : PF : SFN : 19

a. IMSI of UE (in DECIMAL) = 262022008880275
b. N=128 (Look for the formula above to determine the value of N)
c. UE_id = 262022008880275 mod 1024= 147
d. (UE_id mod N) = 147 mod 128=19
e. (T div N) = 128 / 128 = 1

Paging Occasion : PO
Ns = max (1, nB/T) = max (1, 1) =1
i_s = Floor (147/128) mod 1 =1
from i_s table , PO will be 9.

Figure 2 is a schematic representation illustrating Prose service (Lte Direct) architecture. The Lte direct devices discover each other and set up the communication path as defined by 3GPP. The proximity services in 3GPP include the two basic functions which are:
a. D2D discovery and
b. D2D communication.
D2D discovery precedes D2D communication in time, while D2D communication may use information acquired during D2D discovery. D2D discovery enables UE to use the LTE air interface to identify other UE devices that are in proximity. After which, a communication path, a direct link without routing via eNB(s) and possibly core network is set up between Lte devices.

Figure 3 is a schematic representation illustrating direct paging pattern detection using the expression codes. According to the present invention, the two UE’s communicate with each other over shared (Physical Uplink Control Channel (PUCCH). Each UE announces or monitors the expression code in its PUCCH channel allocated by the network. UE1 and UE2 share the Paging Occasion, S-TMSI, TA list with each ProSe path that is established between two UE’s.

Figure 4 is a schematic representation illustrating paging monitoring setup procedure in Lte Direct devices. According to the present invention, a Device-to-Device (D2D) communication is established between first user equipment (UE1) and second user equipment (UE2). The direct communication path between LTE direct devices is used to share paging information such as the paging cycle of each device, S-TMSI to compare the paging and the TA list of each device. The criteria such as device with more battery time left, device receiving most paging messages is used to select paging monitoring device. One of the devices is selected for monitoring, while the other device stops monitoring its Network paging channel, and it monitors only the direct channel to get the notification of Network paging information from the device, which is monitoring.

According to an embodiment of the present invention, stopping the monitoring of the network paging in one of the devices consumes less power and the device still monitors the direct communication path setup between both the devices. When the paging monitoring device receives the paging message from the network, it checks if the paging message is intended for itself or for the other device. If the paging message is intended for the other device, the paging monitoring device notifies the other device by changing the expression code in direct link. With the detection of change in code, the other device establishes the RRC connection with eNB, to receive the incoming communication (such as data/call). And suppose if either of the UEs moves to a different network area i.e., different TA, both the UEs update the TA list of each other. If any of the UE no longer belongs to the same TA list, the paging monitoring for other device, becomes void. The device implicitly detects the change in paging monitoring procedure.

The present embodiments have been described with reference to specific example embodiments; it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the various embodiments. Furthermore, the various devices, modules, and the like described herein may be enabled and operated using hardware circuitry, firmware, and/or software embodied in a machine readable medium. Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.