CLIAMS:claims ,TagSPECI:
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

PROVISIONAL SPECIFICATION
(See section 10, rule 13)

““A method and system for scheduling of system information messages for System Information Window Length 1ms by signaling the System Information message offset number through SIB1”

Tejas Networks Limited
Plot No. 25, JP Software Park,
Electronics City, Phase-1, Hosur Road
Bangalore - 560 100, Karnataka, India

The following specification particularly describes the invention.

Field of the Invention

The present invention relates to communication field, more specifically, to a method for transmitting system information.

Background of the Invention

The Third Generation Partnership Project (3GPP) has initiated the Long Term Evolution (LTE) program to bring new technology, new network architecture, new configurations and new applications and services to wireless networks in order to provide improved spectral efficiency and faster user experiences. Figure 1 shows an overview of an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E- UTRAN) 100 in accordance with the prior art. As shown in Figure 1, E-UTRAN 100 includes three eNodeBs (eNBs) 102, however, any number of eNBs may be included in E-UTRAN 100. The eNBs 102 are interconnected by an X2 interface 108. The eNBs 102 are also connected by an S1 interface 106 to the Evolved Packet Core (EPC) 104 that includes a Mobility Management Entity (MME) 112 and a Serving Gateway (S-GW) 110.

System information (SI) is information that is broadcast within a cell and provides information about configurations and parameters that are common to at least some of the wireless transmit receive units (WTRUs) in the cell. System information messages may include parameters such as network identification, neighbouring cells, channel availability and power control requirements etc. In the existing system message design, depending on different repetition periods, the SIB is included in different SI. The SI is a Radio Resource Control (RRC) message that carries at least one SIB. The SI is sent on the radio frame periodically. Each SIB includes a series of relevant SI parameters.
In the long-term evolution (LTE) system, system information may be divided into main information block (MIB), system information block 1 (SIB1) and ordinary system information (SI).
Wherein the MIB is transmitted in a broadcasting channel with a transmitting cycle of 40 milliseconds, and the MIB is repeatedly transmitted in sub-frame #0 of each wireless frame within its transmitting cycle. SIB1 is transmitted in a downlink shared channel with a scheduling cycle of 80 milliseconds, and SIB1 is repeatedly transmitted in sub-frame #5 (sub-frame number starts from 0) of a wireless frame satisfying SFN % 2=0 (wherein SFN is the system frame name) within its scheduling cycle; and other system parameters are included in other system information blocks (SIB). The contents of system parameters comprise service cell information, cell reselection information and adjacent cell information of intra-frequency, inter-frequency and other radio access technologies (RAT) etc.
The above SIBs are mapped into different System Information (SI) messages to realize scheduling, that is, the SIBs are defined according to their contents, wherein SI serves as a scheduling unit, the scheduling information of these SIs are included in SIB1, and the scheduling information specifically comprises a transmitting window w, a scheduling cycle n and so on. The order that the SI appears in the scheduling information of SIB1 is called as scheduling order n, the transmitting windows of all SIs are the same, but the scheduling cycles may be different. The transmitting window of the SI is a limited time range, within which the SIBs mapped into the same SI are repeatedly transmitted, but it is not determined in which sub-frame the transmission is conducted, that is, a terminal needs to try to receive and decode the SI in each sub-frame within the transmitting window. In the LTE system, to simplify the scheduling process, the relation between the scheduling cycles N of all SIs is in general that one is simply multiple of another, and they all have even number of frames. For example, the scheduling cycle N may be 8 frames, 16 frames and so on, which makes a certain SFN to become a common multiple of some SIs, i.e. satisfying SFN % N=0.To facilitate description, the above SI is called SI group on the SFN in the following description.
The scheduling rule of SI is described as follows: supposing that the size of the transmitting window is w sub-frames, the scheduling cycle of a certain SI is N and the scheduling order thereof is n, then the starting wireless frame and sub-frame of the transmitting window of the system information may be represented by the following formulae: SFN % N=COUNT+floor(w*(n-1)/10), sub-frame=(w*(n-1)) % 10, wherein COUNT is a constant and may be 0 or 8 for example. If COUNT is larger than or equal to N, then COUNT shall be modified to be COUNT % N. It can be seen that when n=1, sub-frame=0, that is, the transmitting window of SI with n=1 begins from sub-frame #0 of the wireless frame satisfying SFN % N=COUNT. For the SIs with n larger than 1, following the SI with n=1, they shall be continuously transmitted within their respective transmitting windows in sequence. For example, it is assumed that there are 7 SIBs all together, i.e. SIB2, SIB3, SIB4, SIB5, SIB6, SIB7 and SIB8, and these SIBs are mapped into 7 SIs, i.e. SI-1, SI-2, SI-3, SI-4, SI-5, SI-6, and SI-7 , in a one-to-one manner and their scheduling cycles are 160 ms, 320 ms, 640 ms, 640 ms, 1280 ms, 1280 ms and 1280 ms, respectively.
In LTE, for system information window length of 1 millisecond, the number of system information messages that can be transmitted is limited. It is specified in the LTE system that other SIs are not allowed to be transmitted in sub-frame #5 satisfying SFN % 2=0 in order to avoid mixing SIB1 and other SIs on the same sub-frame. Further uplink subframe and special subframe for which special subframe configuration does not support PDSCH transmission and MBSFN subframes block the transfer of system information message.
Thus, there is a need to propose an alternative method to overcome the above mentioned limitation so that transmitting conflict between the SI and SIB1 can be avoided.
Brief description of the drawings

A more detailed understanding may be had from the Detailed Description below, given by way of example in conjunction with drawings appended hereto.
Figure 1 shows an overview of a typical E-UTRAN.
Figure 2 shows an example wireless communication system including a plurality of WTRUs and an eNB according to one embodiment.
Figure 3 is a block diagram of a WTRU and the eNB of Figure 2.
Figure 4 shows a flow chart of a method for scheduling of system information messages for System Information Window Length 1ms, according to one embodiment of the present invention.
Figure 5 shows an example of SIB 1 having a scheduling information list with ‘si-MessageNumber’ according to one embodiment of the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.

Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

Description of the Invention
When referred to hereafter, the term "wireless transmit/receive unit (WTRU)" includes, but is not limited to, a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a computer, or any other type of user device capable of operating in a wireless environment. When referred to hereafter, the term "base station" includes, but is not limited to, a Node B, a site controller, an access point (AP), or any other type of interfacing device capable of operating in a wireless environment.
Figure 2 shows a wireless communication system 200 including a plurality of WTRUs 210 and an e Node B (eNB) 220. As shown in Figure 2, the WTRUs 210 are in communication with the eNB 220. Although three WTRUs 210 and one eNB 220 are shown in Figure 2, it should be noted that any combination of wireless and wired devices may be included in the wireless communication system 200.
Figure 3 is a functional block diagram 300 of a WTRU 210 and the eNB 220 of the wireless communication system 200 of Figure 2. As shown in Figure 2, the WTRU 210 is in communication with the eNB 220. The WTRU 210 is configured to receive and process emergency and non-emergency SI messages. In addition to the components that may be found in a typical WTRU, the WTRU 210 includes a processor 315, a receiver 316, a transmitter 317, and an antenna 318. The WTRU 210 may also include a user interface 321, which may include, but is not limited to, an LCD or LED screen, a touch screen, a keyboard, a stylus, or any other typical input/output device. The WTRU 210 may also include memory 319, both volatile and non- volatile as well as interfaces 320 to other WTRU's, such as USB ports, serial ports and the like. The receiver 316 and the transmitter 317 are in communication with the processor 315. The antenna 318 is in communication with both the receiver 316 and the transmitter 317 to facilitate the transmission and reception of wireless data. [0024] In addition to the components that may be found in a typical eNB, the eNB 220 includes a processor 325, a receiver 326, a transmitter 327, and an antenna 328. The receiver 326 and the transmitter 327 are in communication with the processor 325. The antenna 328 is in communication with both the receiver 326 and the transmitter 327 to facilitate the transmission and reception of wireless data. The eNB 220 is configured to transmit and process emergency and non-emergency SI messages.
As shown in the flow chart of figure 4, in the method UE receives scheduling information list in SIB1. The scheduling sequence is given by
SchedulingInfo ::= SEQUENCE {
si-MessageNumber ENUMERATED { si1, si2, si3, si4, si5, si6, si7, si8, si9, si10,…..maxSIMessage}, (OPTIONAL)
si-Periodicity ENUMERATED { rf8, rf16, rf32, rf64, rf128, rf256,rf512}
sib-MappingInfo SIB-MappingInfo
}
The UE retrieves the SI record from the scheduling information list. Further, UE retrieves SI number from SI record, if all the SI records are not processed. Upon retrieving the SI number from the SI record, the UE calculates SI window form SI number for scheduling the SI messages.
Figure 5 shows an example of SIB 1 having a scheduling information list with ‘si-MessageNumber’ according to one embodiment of the present invention. The solution proposed removes the limitation on the number of System Information messages that can be transmitted for System Information window length of 1millisecond by a method of transmission of SI messages on discontinuous SI-windows by signaling the System Information message offset number through SystemInformationBlockType1 by which the number of System Information messages that can be transmitted is increased to the maximum limit of 32.

“A method and system for scheduling of system information messages for System Information Window Length 1ms by signaling the System Information message offset number through SIB1”

The present invention relates to a method for transmitting system information. More particularly, the present invention relates to scheduling of system information messages for System Information Window Length 1ms by signaling the System Information message offset number through SIB1.