EXHIBIT 11

Case 1:20-cv-22051-JEM Document 1-14 Entered on FLSD Docket 05/15/2020 Page 1 of 16
(12) United States Patent 

Roberts et al. 

USOO 8600383B2 

(10) Patent No.: US 8,600,383 B2 

(45) Date of Patent: *Dec. 3, 2013 

(54) 

(75) 

(73) 

(*) 

(21) 

(22) 

(65) 

(63) 

(51) 

(52) 

APPARATUS AND METHOD FOR MAKING 

MEASUREMENTS IN MOBILE 

TELECOMMUNICATIONS SYSTEM USER 

EQUIPMENT 

Inventors: Gideon Roberts, Staffordshire (GB); 

Robert Harrison, Birmingham (GB); 

Richard George, Birmingham (GB); 

Gjalt Gerrit De Jong, Leuven (BE) 

Assignee: BlackBerry Limited, Waterloo, Ontario 

(CA) 

Notice: Subject to any disclaimer, the term of this 

patent is extended or adjusted under 35 

U.S.C. 154(b) by 0 days. 

This patent is Subject to a terminal dis 

claimer. 

Appl. No.: 13/617.241 

Filed: Sep. 14, 2012 

Prior Publication Data 

US 2013/OO65591 A1 Mar. 14, 2013 

Related U.S. Application Data 

Continuation of application No. 13/244,776, filed on 

Sep. 26, 2011, now Pat. No. 8,290,491, which is a 

continuation of application No. 12/267,412, filed on 

Nov. 7, 2008, now Pat. No. 8,351,940, which is a 

continuation of application No. 10/921,079, filed on 

Aug. 18, 2004, now Pat. No. 7,463,887. 

(58) Field of Classification Search 

USPC ............................ 455/435.1-435.3, 436–444 

See application file for complete search history. 

(56) References Cited 

U.S. PATENT DOCUMENTS 

5,452,471 A 9/1995 Leopold et al. 

5,802,473 A 9/1998 Rutledge et al. 

5,822,696 A * 10/1998 Bergkvist ...................... 455,436 

5.999,814 A 12/1999 Cuffaro et al. 

6,138,018 A * 10/2000 Pashtan et al. ............. 455,435.2 

6,377,803 B1 * 4/2002 Ruohonen ..................... 455,434 

(Continued) 

FOREIGN PATENT DOCUMENTS 

FR 2742291 6, 1997 

GB 238,5745 8, 2003 

OTHER PUBLICATIONS 

U.S. Notice of Allowance for U.S. Appl. No. 10/921,079, dated Sep. 

2, 2008, 8 pages. 

(Continued) 

Primary Examiner — Dominic E Rego 

(74) Attorney, Agent, or Firm — Finnegan, Henderson, 

Farabow, Garrett & Dunner LLP 

(57) ABSTRACT 

A method and apparatus for selecting cells in a mobile tele 

communications system, the system comprising a network of 

a plurality of cells of a Universal Mobile Telecommunica 

tions Systems (UMTS) and a network of a plurality of cells of 

a second Radio Access Technology (RAT), the method com 

prising, at a user equipment device: when in UMTS mode, 

flagging in a neighboring cell list stored on the user equip 

ment device information for a cell of a second RAT which is Int. C. 

H0474/00 (2009.01) known to be unsuitable for selection. Information from the 

U.S. C neighboring cell list information for the flagged cell may be 

USPG 45S/435.2:455/434:455/.435.1 removed, in particular for a limited period of time. 

455/436 97 Claims, 5 Drawing Sheets 

C t 2001 witHRs 

------- Y - 

identify high 202 -- sight 20 

Check if identified Identify next 204 -1 cell issuitable highest ranked cell 

206 Suitable 

Successful 208 cell reselection 

Flag cell as being unsuitable 

207 

 

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US 8,600,383 B2 

Page 2 

(56) References Cited 2004/0192313 A1* 9/2004 Otting ........................... 455,446 

2005.0003817 A1 1/2005 Ormson et al. ............ 455,435.2 

U.S. PATENT DOCUMENTS 2005/0044130 A1 2/2005 Sillasto et al. 

2005.0075074 A1 4/2005 Benson et al. 

6,393,279 B1* 5/2002 Lee ............................ 455,426.1 2005, 007987O A1 4/2005 Ricket al. 

6,553,231 B1 4/2003 Karlsson et al. 2005/0O85232 A1 4/2005 Laitinen et al. 

7,123.910 B2 * 10/2006 Lucidarme et al. ........... 455,434 2005/0090224 A1 4/2005 Dorsey et al. 

7,127,253 B2 10/2006 Chen 2005, 0186984 A1 8/2005 Lundell et al. 

7,133,702 B2 * 1 1/2006 Amerga et al. ............... 455,574 2005/0277416 A1 12/2005 Tolli et al. 

7,184,710 B2 2/2007 Hogan 2006,0009158 A1 1/2006 Bernhard et al. 

7,266,381 B2 * 9/2007 Charles ...................... 455,456.4 2007,0298790 A1 12/2007 Ormson et al. 

7.286.801 B2 10/2007 Amerga et al. 2008/0039084 A1 2/2008 Benveniste et al. ........... 455,434 

7,308,258 B2 * 12/2007 Demir et al. .................. 455,434 2009, 0207.774 A1 8, 2009 Lee et al. 

7,436,843 B2 * 10/2008 Gustafsson et al. .......... 370/401 7.463,887 B2 12/2008 Roberts et al. OTHER PUBLICATIONS ck 

25. E: ck 3. is . . . . . . . . . . . . . . . . . . . . . 3. U.S. Notice of Allowance for U.S. Appl. No. 12/267,412, dated Aug. 

7,596,378 B1* 9/2009 Nizri et al. ... 455/448 31, 2012, 7 pages. 7,634,272 B2 * 12/2009 Yamashita et al 455,444 U.S. Notice of Allowance for U.S. Appl. No. 13/244.776, mailed Jun. 

7,949,337 B2 * 5/2011 Choi ............................. 455,440 13, 2012, 8 pages. 2001/0041572 A1 1 1/2001 Lundqvist U.S. Office Action for U.S. Appl. No. 10/921,079, dated Mar. 17, 

2001/0044301 A1 11/2001 Moore 2008, 11 pages. 

2002/0032032 A1 3f2002 Haumont et al. ............. 455,436 U.S. Office Action for U.S. Appl. No. 10/921,079, dated Sep. 7, 2007, 

2002fO197992 A1* 12/2002 NiZri et al. .................... 455,435 9 pages. 

2003/004.0311 A1 2, 2003 Choi U.S. Office Action for U.S. Appl. No. 12/267,412, datedMar. 9, 2012, 

2003/O125073 A1* 7/2003 Tsai et al. ..................... 455,552 5 pages. 

2004.0043798 A1 3/2004 Amerga et al. U.S. Office Action for U.S. Appl. No. 13/244,776, dated Dec. 16, 

2004/0109431 A1* 6/2004 Abrahamson et al. ........ 370,342 2011, 7 pages. 

2004/0162074 A1* 8, 2004 Chen .................. 455,437 

2004/0180656 A1* 9/2004 Stephan et al. ............... 455,434 * cited by examiner 

 

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U.S. Patent Dec. 3, 2013 Sheet 1 of 5 US 8,600,383 B2 

3G SGSN CBC 

Fig. 1 

 

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U.S. Patent Dec. 3, 2013 Sheet 2 of 5 US 8,600,383 B2 

Carry out 

200 measurementS 

Identify highest 

2O2 ranked cell 

20 

Check if identified It st 

204 cell is suitable ranked cell 

N Flag cell as 

2O6 being unsuitable 

Y 207 

208 Successful 

cell reselection 

Fig. 2 

 

 

 

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U.S. Patent Dec. 3, 2013 Sheet 3 of 5 US 8,600,383 B2 

Carry out 

3O2 measureinentS 

34 

3O4. Identify highest 

ranked cell Identify next 

highest 

307 ranked cell 

END N/1dentified cell is 33 Y -- a same RAT cell? N 

Any cells left to 

305 check? 

315 

306 

Check if identified 

cell is suitable 

Cell barred for 

time Tharred 

Identified cel 

deemed unsuitable 

owing to cell 

information or 

transmission Flag cell as 

being unsuitable problems? 

309 

Omit from list 

previously 

identified cell 

Successful 

cell reselection 

316 Fig. 3 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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U.S. Patent Dec. 3, 2013 Sheet 4 of 5 US 8,600,383 B2 

34 Layer 3 

NAS 

136 

Layer 1 - Physical Layer 

Fig. 4 

 

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U.S. Patent Dec. 3, 2013 Sheet 5 of 5 US 8,600,383 B2 

08/ 

-OJOJN Jossooo Id 

 

 

 

 

 

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US 8,600,383 B2 

1. 

APPARATUS AND METHOD FOR MAKING 

MEASUREMENTS IN MOBILE 

TELECOMMUNICATIONS SYSTEM USER 

EQUIPMENT 

CROSS REFERENCE TO RELATED 

APPLICATION 

The present application is a continuation application of 

patent application Ser. No. 13/244,776, filed Sep. 26, 2011 

(now allowed) now U.S. Pat. No. 8,290,491, which is a con 

tinuation of application Ser. No. 12/267,412 filed Nov. 7. 

2008 (now allowed) now U.S. Pat. No. 8,351,940, which is a 

continuation of application Ser. No. 10/921,079 filed Aug. 18, 

2004, (now U.S. Pat. No. 7,463,887 issued Dec. 9, 2008), the 

contents of which are incorporated herein by reference. 

BACKGROUND 

1. Technical Field 

This application relates to a dual mode mobile telecommu 

nication device in general (for instance a UMTS (Universal 

Mobile Telecommunications System) and GSM (Global Sys 

tem for Mobile Communications) dual mode device), and to 

an apparatus and method for selecting cells in mobile tele 

communications system user equipment. The invention also 

relates to Mobile Stations (MS) and User Equipment (UE) 

which Support at least two Radio Access Technologies 

(RATs). 

2. Description of the Related Art 

The approaches described in this section could be pursued, but are not necessarily approaches that have been previously 

conceived or pursued. Therefore, unless otherwise indicated 

herein, the approaches described in this section are not prior 

art to the claims in this application and are not admitted to be 

prior art by inclusion in this section. 

In a typical cellular radio system, mobile user equipment 

(UE) communicates via a radio access radio network (RAN) 

to one or more core networks. User equipment (UE) com 

prises various types of equipment such as mobile telephones 

(also known as cellular or cellphones), laptops with wireless 

communication capability, personal digital assistants (PDAS) 

etc. These may be portable, hand held, pocket sized, installed 

in a vehicle etc and communicate Voice and/or data signals with the radio access network. 

The radio access network covers a geographical area 

divided into a plurality of cell areas. Each cell area is served 

by at least one base station, which may be referred to as a 

Node B. Each cell is identified by a unique identifier which is 

broadcast in the cell. The base stations communicate at radio 

frequencies over an air interface with the UEs within range of 

the base station. Several base stations may be connected to a 

radio network controller (RNC) which controls various 

activities of the base stations. The radio network controllers 

are typically connected to a core network. 

UMTS is a third generation public land mobile telecom 

munication system. Various standardization bodies are 

known to publish and set standards for UMTS, each in their 

respective areas of competence. For instance, the 3GPP 

(Third Generation Partnership Project) has been known to 

publish and set standards for GSM (Global System for 

Mobile Communications) based UMTS, and the 3GPP2 

(Third Generation Partnership Project 2) has been known to 

publish and set standards for COMA (Code Division Multiple 

Access) based UMTS. Within the scope of a particular stan 

dardization body, specific partners publish and set standards 

in their respective areas. 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

2 

Considera wireless mobile device, generally referred to as 

user equipment (UE), that complies with the 3GPP specifica 

tions for the UMTS and with GSM protocols. The 3GPP 

25.331 specification, v.3.18.0, referred to hereinas the 25.331 

specification, addresses the subject of the Radio Resource 

Control (RRC) protocol specification. The 3GPP 25.304 

specification, v.3.14.0, referred to herein as the 25.304 speci 

fication, addresses the subject of UMTS User Equipment 

(UE) procedures in idle mode and procedures for cell rese 

lection in connected mode between the UMTS Terrestrial 

Radio Access Network (UTRAN) and the UE. 

Such a UE undertakes frequent measurement procedures. 

Clause 8.4 of the 25.331 standard and its sub-clauses and 

clause 14 and its sub-clauses relate to the measurement pro 

cedures to be undertaken by the UE as do clause 5 and its 

sub-clauses of the 25.304 specification. Both the 25.331 stan 

dard (and in particular clause 8.4 and its sub-clauses and 

clause 14 and its sub-clauses) and the 25.304 standard (and in 

particular clause 5.2.3.1 and its sub-clauses) are incorporated 

herein by reference. 

When camped on a UMTS cell, the UE shall regularly 

search for a better cell according to the cell reselection crite 

ria. If a better cell is found, the UE should attempt to select 

that cell. A change of cell may imply a change of RAT. 

The 3GPP specifications allow a dual-mode UE to repeat 

edly attempt to camp on a cell using another RAT when the 

cell is known to be unavailable just because it happens to have 

the strongest available transmission signal. 

For a dual-mode UE operating in UMTS idle mode (or 

CELL PCH, URA PCH or CELL FACH states) and a GSM 

cell is initially found to be the best cell, problems can arise if 

the GSM cell is unsuitable or unavailable for selection, for 

example, if synchronization cannot be achieved or system 

information cannot be decoded. Each unsuccessful attempt to 

reselect to the unsuitable?unavailable GSM cell results in a 

short loss of service, and the UE will be unresponsive to 

attempts at incoming communication. It will therefore be 

seen that there is a need to avoid Such repeated interruptions. 

Further, battery power in the UE can also be wasted by repeated attempts of the UE to change its operational mode 

between RATs every few seconds. With reference to clause 

5.5.2.2.3 of the 3GPP 25.133 specification, v 3.18.0, the 

minimum interruption time when attempting to move from a 

UMTS cell to a GSM cell is 40 ms, and is likely to be 

considerably longer, perhaps even greater than 100 ms. 

There are thus proposed strategies for User Equipment 

(UE) measurement procedures, which are appropriate in 

UMTS idle mode and during cell reselection to a GSM cell. A 

number of such strategies are detailed below. 

Other aspects and features of the present invention will 

become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments 

of an apparatus and method for carrying out User Equipment 

(UE) procedures in idle mode and procedures for cell rese 

lection in connected mode. 

BRIEF DESCRIPTION OF THE DRAWINGS 

Embodiments of the present invention will now be 

described, by way of example only, with reference to the 

attached drawings, in which: 

FIG. 1 shows an overview of a network and UE device; 

FIG. 2 is a flow diagram illustrating a first embodiment of 

a process for cell selection; 

FIG.3 is a flow diagram illustrating a second embodiment; 

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US 8,600,383 B2 

3 

FIG. 4 is a block diagram illustrating an embodiment of a 

protocol stack apparatus provided with a RRC block, in 

accordance with the present application; and 

FIG. 5 is a block diagram illustrating a mobile device, 

which can act as a UE and co-operate with the apparatus and 

methods of FIGS. 1 to 5. 

The same reference numerals are used in different figures 

to denote similar elements. 

DETAILED DESCRIPTION OF THE DRAWINGS 

A method and apparatus for making measurements in 

mobile telecommunications system user equipment are 

described. In the following description, for the purposes of 

explanation, numerous specific details are set forth in order to 

provide a thorough understanding of the present invention. It 

will be apparent, however, to one skilled in the art that the 

present invention may be practiced without these specific 

details. In other instances, well-known structures and devices 

are shown in block diagram form in order to avoid unneces 

sarily obscuring the present invention. 

The needs identified in the foregoing Background, and 

other needs and objects that will become apparent from the 

following description, are achieved by, in one aspect, a 

method for selecting cells in a mobile telecommunications 

system, the system comprising a network of a plurality of 

cells and at least one user equipment device. The method 

comprises, at the user equipment device, when in UMTS 

mode, flagging in a neighboring cell list stored on the user 

equipment device information for a cell of a second RAT 

which is known to be unsuitable for selection. 

In other aspects, the invention encompasses an apparatus 

and a computer-readable medium configured to carry out the 

foregoing steps. In particular, the method may be imple 

mented in a mobile telecommunications device, with or with 

out Voice capabilities, or other electronic devices such as 

handheld or portable devices. 

There is also provided a method of maintaining informa 

tion relating to selecting cells that are potentially suitable for 

a user equipment to select/camp on in a telecommunications 

system, the system comprising a network of a plurality of 

cells of a Universal Mobile Telecommunications System and 

a network of a plurality of cells of a second Radio Access 

Technology (RAT), the system further comprising at least one 

user equipment device, the method comprising, at the user 

equipment device: Storing information relating to cells of the 

network; from the stored maintained information, identifying 

a cell which meets a cell selection criterion; determining 

whether the identified cell is of the other RAT; and, if the 

identified cell is determined to be of the other RAT: determin 

ing whether the identified cell is suitable for selection; and if 

the identified cell is not suitable, flagging the cell as being 

unsuitable for selection. 

FIG. 1 shows an overview of a network and a UE device. 

Clearly in practice there may be many UE devices operating 

with the network but, for the sake of simplicity, FIG. 1 only 

shows a single UE device. For the purposes of illustration, 

FIG. 1 also shows a network having a few components. It will 

be clear to a person skilled in the art that in practice a network 

will include far more components than those shown. 

FIG. 1 shows an overview of the radio access network 702 

(RAN) used in a UMTS system or a GSM network. The 

network 702 as shown in FIG. 1 comprises three Radio Net 

work Subsystems (RNS) 2. Each RNS has a Radio Network 

Controller (RNC)4. Each RNS 2 has one or more Node B 6 

which are similar in function to a Base Transmitter Station of 

a GSM radio access network. User Equipment UE 700 may 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

4 

be mobile within the radio access network. Radio connections 

(indicated by the straight dotted lines in FIG. 1) are estab 

lished between the UE and one or more of the Node Bs in the 

UTRAN. 

The RNC 4 controls the use and reliability of the radio 

resources within the RNS 2. Each RNC 4 may also be con 

nected to a 3G mobile switching center 10 (3G MSC) and a 

3G serving GPRS support node 12 (3G SGSN). 

An RNC 4 controls one or more Node B's. An RNC plus its 

Node B's together make up an RNS 2. A Node B controls one 

or more cells. Each cell is uniquely identified by a frequency and a primary scrambling code (primary CPICH in FDD, 

primary CCPCH in TOO). 

Generally in UMTS a cell refers to a radio network object 

that can be uniquely identified by a UE from a cell identifier 

that is broadcast over geographical areas from a UTRAN 

access point. A UTRAN access point is a conceptual point 

within the UTRAN performing radio transmission and recep tion. A UTRAN access point is associated with one specific 

cell i.e., there exists one UTRAN access point for each cell. It 

is the UTRAN-side endpoint of a radio link. A single physical 

Node B 6 may operate as more than one cell since it may 

operate at multiple frequencies and/or with multiple scram 

bling codes. 

Section 5.2.6 of the 25.304 standard sets out the cell rese 

lection criterion. 

In the following description, reselection between cells 

operating in FDD mode and attempting to change to GSM 

mode will be considered. However the technique is also appli 

cable in reselection between cells operating in TDD mode and 

attempting to change to GSM mode. The technique is also 

applicable for reselection between CDMA2000 cells/GSM 

cells/GPRS cells. 

The Network Operator transmits in the UMTS cell to all 

UEs in the UMTS cell, over the broadcast channel (BCCH), a 

GSM Neighbouring Cell list. Alternatively, the list is derived 

at the UE from information transmitted by the Network 

Operator. This list contains information relating to GSM cells 

which are adjacent to, or in the vicinity of the UMTS cell in 

question. 

Included in the GSM neighboring cell list is information 

relating to the transmission frequency of each neighboring 

GSM cell respectively. Accordingly, the UE has prior knowl 

edge, at least in one mode of operation, of all the frequencies 

at which the neighboring GSM cells transmit. As such, the UE 

can scan these frequencies for signal strengths of the respec 

tive GSM cells. Once the respective frequencies have been 

scanned, the UE populates the GSM neighboring cell list with 

information relating to cell ranking according to the cell 

reselection criteria for each cell at its respective transmission 

frequency. 

In a similar fashion, a UMTS neighboring cell list is trans 

mitted or compiled, thereby allowing the UE to have prior 

knowledge of the transmission frequencies of the neighbor 

ing UMTS cells and to scan these frequencies accordingly. 

This list is populated with transmission frequency informa 

tion in a similar fashion to the way it is carried out for the 

GSM neighboring cell list. 

The GSM neighboring cell list, as transmitted by the Net 

work Operator, does not take into account the status of the 

GSM cells; i.e. a cell may be temporarily barred but will still 

be listed in the GSM neighboring cell list. 

As will be discussed below, when the UE has determined 

that a GSM cell is barred, the GSM cell is removed by the UE 

from the GSM neighboring cell list stored locally at the UE 

until expiry of a time interval, Tbarred This time interval is 

configurable, but a suitable time period may be 300 seconds. 

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5 

During this time period, Tbarred, the “barred cell is not to be 

considered as a candidate for reselection by the UE. 

The GSM neighboring cell lists may contain GSM cells 

that are barred and which are to be removed from the lists until 

expiry of the time interval.T. Alternatively, there may be 

a list for containing details of cells which are barred and 

details of the barred/unsuitable cell is added to this list. The 

barred cells may keep their indices in the list but no measure 

ment is performed, i.e., no scan at the frequency of that cell is 

made. The UE may re-read and/or re-build the GSM neigh boring cell list upon expiry of the time interval T for the 

or all barred cells, if more than one barred cell is found. The 

time, T. may be set individually for each barred cell. 

A process of a cell reselection process is illustrated in FIG. 

2 which is a flow chart illustrating the operation of a UE 

device. At intervals the UE device carries out measurements, 

step 200. The UE carries out measurements on neighboring cells according to its capability. 

The UE then determines whether the measurement data 

meets a predetermined criterion and stores the measurement 

data in an order relative to the meeting of the criterion (a cell 

ranking list). An example of the cell reselection criteria is 

given in 5.2.6 of the 25.304 specification. 

Table 1 shows an example of the signal measurement 

results for a UE, with the highest ranked cells being shown at 

the top of the table and the lowest ranked cells shown at the 

bottom. 

TABLE 1. 

CA f GSM 

CD f, GSM 

CB f UMTS 

C. Fs GSM 

C. f UMTS 

Co. f GSM 

CC fs GSM 

C fs GSM 

where C indicates a signal from cell A, findicates a signal 

at frequency f. GSM indicates that the cell is a GSM cell and 

UMTS indicates that the cell is a UMTS cell. Typically, signal 

measurement results for the GSM network and for the UMTS 

network are compiled in separate tables for each network and 

a comparison or consolidation between the two tables is made 

prior to determination of the highest ranked cell. However, for 

the sake of simplicity in this and following examples a con 

solidated table of results will be used. 

When compiling the ranking list of the various neighboring 

GSM and UMTS cells, the time period for the comparison 

between GSM cells and UMTS cells is configurable; for 

further details see clause 5.2.6 of the 25.304 specification. 

The UE uses these measurement results to identify the 

highest ranked cell, step 202. In the example shown in table 1 

this is the signal from GSM cell A at frequency f. The UE 

then checks whether the identified cell at the identified fre 

quency is suitable, step 204. If the identified cell at the iden 

tified frequency is suitable, step 206, successful cell reselec 

tion has occurred, step 208, and the UE continues operation. 

However the identified cell may not be suitable. For example, 

if the system information from a cell which informs the UE 

how to connect to the cell has an error in it, then the cell is 

deemed to be unsuitable. 

However if the identified cell is not suitable at step 206, the 

UE then flags the identified cell as unsuitable, step 207, for 

instance using an identifier, or removes the unsuitable cell 

from the neighboring cell list. The cell may be flagged as 

unsuitable, to leave vacant the information relating to the 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

6 

unsuitable cell from the maintained neighboring cell list. The 

UE then proceeds to identify the next highest ranked cell, step 

210. In the example shown in table 1, this is GSM cell 0 at a 

frequency f, i.e., a different GSM cell operating at a different 

frequency as the previously identified cell. The UE then 

attempts to connect with this identified cell at step 204 and if 

successful a successful cell connection with GSM cell Dat 

frequency his made. Otherwise the UE continues to identify 

the next highest ranked cells and to attempt to connect with 

these cells until a successful connection is made or connec 

tion to all potential cells has failed, in which case the UE 

returns a message to the user, for instance "emergency calls 

only” or “no network coverage'. 

The UE then periodically repeats the search for a suitable 

cell omitting from the search any cells which are flagged as 

unsuitable. Thus, if a GSM cell is not suitable or is barred, the 

UE does not repeatedly attempt to camp on to the unsuitable/ 

barred cell. 

If the UE Selects UMTS cell B because GSM cells A and 

Dare unsuitable, then during the next cell reselection evalu 

ation, cells A and Dare excluded from the next cell reselection 

process. Thus, if the GSM cell is not suitable or barred, the UE 

does not repeatedly attempt to camp on to the unsuitable/ 

barred cell. 

Note that the process may also be carried out without 

identifying the highest ranked cell (i.e., steps 200, 202 and 

210 may be omitted). In this case, the UE, when in UMTS 

mode, flags in a neighboring cell list stored on the user equip 

ment device information for a cell of the second RAT which 

is known to be unsuitable for selection. 

In an embodiment of the invention, when an identified cell 

is deemed unsuitable, it is omitted from the GSM neighboring 

cell list. Alternatively, the identified cell can be added to a list 

of cells known to be unsuitable. During the next reselection 

evaluation, the UE performs measurements on cells listed in 

the GSM neighboring cell list but omits the cell previously 

identified as the unsuitable/barred cell. 

FIG.3 shows a further embodiment of the technique. In this 

embodiment, the UE carries out measurements to search for 

the highest ranked cell in each cell type (i.e. GSM or UMTS) required according to its capabilities, step 302. An example of 

the measurements made by a UE is shown in table 2, with the 

highest ranked cells being shown at the top of the table and the 

lowest ranked cells shown at the bottom. 

TABLE 2 

CA f GSM 

CD f7 GSM 

CB f UMTS 

C. Fs GSM 

C. f UMTS 

Co. f GSM 

C Fs GSM 

C F6 GSM 

The UE then identifies the highest ranked cell, step 304. 

For the results shown in table 2, this is cell A (which happens 

to be a GSM cell) at frequency k The UE then performs a 

check that this is a GSM cell, step 305 and, if the check 

confirms that this is a GSM cell, the UE checks if this iden 

tified GSM cell is suitable, step 306. (If, at step 305 the UE 

determines that the cell is another UMTS cell, the process according to this embodiment of the invention terminates, 

step 307, as reselection of a same RAT cell is not the focus of 

the present discussion.) If the GSM cell is suitable, step 308, 

a successful cell reselection is made, step 310. However, if the 

cell is not suitable because it is barred for any reason (e.g. it is 

Case 1:20-cv-22051-JEM Document 1-14 Entered on FLSD Docket 05/15/2020 Page 11 of 16
US 8,600,383 B2 

7 

not suitable owing to cell information (for example because 

the cell is not on the same public land mobile network 

(PLMN) as that selected by the UE)), or not available because 

of transmission problems (such as Synchronization cannot be 

achieved/system information cannot be decoded) step 312, 

the cell is barred as a candidate for reselection for the time 

T step 315. If there are cells left to check in Table 2, step 

313, the UE then identifies the next highest ranked cell (fre 

quency f, cell D), step 314, and checks if this is a GSM cell 

again, step 305. The process continues round the loop as 

above until successful cell reselection 310 takes place, or a 

re-scanning step 302 is required. When the rescan step 302 

does take place, the UE removes details of the barred cell 

from the table for the time T. As such, the barred cell is 

not considered as a candidate for reselection for this time 

interval. The UE may check for remaining identified cells 

(step 313) before starting the new cell reselection measure 

ment. If a suitable cell is found then it is selected and the cell 

reselection evaluation process is started on the new cell. 

This continues until a suitable cell is identified, the next 

best available cell is a UMTS cell or connection to all poten tial cells has failed, in which case the UE returns a message to 

the user, for instance “emergency calls only” or “no network 

coverage'. The UE then periodically searches for a suitable 

cell. 

When a GSM cell is deemed unsuitable, for whatever rea 

son, the cell in question can be explicitly removed (barred) 

from the cell reselection measurements for a defined period of 

time as soon as it is determined that it is unsuitable or barred. 

During this time period, the cell will not be considered as a 

candidate for cell reselection. 

Examples of the second RAT are GSM, GPRS or 

CDMA2000. The following are examples of barred or unsuit 

able cells: a cell with an “Intra-frequency cell-reselection 

indicator set to “not allowed'; or a cell in which a service is 

not available. Such as an emergency call service, a data ser 

Vice (such as a packet data service e.g. GPRS or email). Referring to the drawings, FIG. 4 is a block diagram illus 

trating an embodiment of a UMTS protocol stack apparatus. 

The RRC block 136 a sub layer of Layer 3 130 of a UMTS 

protocol stack 100. The RRC 136 exists in the control plane 

only and provides an information transfer service to the non 

access stratum NAS 134. The RRC 136 is responsible for 

controlling the configuration of radio interface Layer 1110 

and Layer 2120. When the UTRAN wishes to change the UE 

configuration it will issue a message to the UE containing a 

command to invoke a specific RRC procedure. The RRC 136 

layer of the UE decodes this message and initiates the appro priate RRC procedure. Generally when the procedure has 

been completed (either successfully or not) then the RRC 

sends a response message to the UTRAN (via the lower 

layers) informing the UTRAN of the outcome. It should be 

noted that there are a few scenarios where the RRC will not 

issue a response message to the UTRAN and, in those cases 

the RRC need not and does not reply. Cell reselection may be 

implemented in the RRC. 

Turning now to FIG. 5, FIG. 5 is a block diagram illustrat 

ing a mobile device, which can act as a UE and co-operate with the apparatus and methods of FIGS. 1 to 4, and which is 

an exemplary wireless communication device. Mobile station 

700 is preferably a two-way wireless communication device 

having at least Voice and data communication capabilities. Mobile station 700 preferably has the capability to commu 

nicate with other computer systems on the Internet. Depend 

ing on the exact functionality provided, the wireless device 

may be referred to as a data messaging device, a two-way 

pager, a wireless e-mail device, a cellular telephone with data 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

8 

messaging capabilities, a wireless Internet appliance, or a 

data communication device, as examples. 

Where mobile station 700 is enabled for two-way commu 

nication, it will incorporate a communication Subsystem 711, 

including both a receiver 712 and a transmitter 714, as well as 

associated components such as one or more, preferably 

embedded or internal, antenna elements 716 and 718, local 

oscillators (LOS) 713, and a processing module Such as a 

digital signal processor (DSP) 720. As will be apparent to 

those skilled in the field of communications, the particular design of the communication subsystem 711 will be depen 

dent upon the communication network in which the device is 

intended to operate. For example, mobile station 700 may 

include a communication Subsystem 711 designed to operate 

within the MobitexTM mobile communication system, the 

DataTACTM mobile communication system, GPRS network, 

UMTS network, or EDGE network. 

Network access requirements will also vary depending 

upon the type of network 702. For example, in the Mobitex 

and DataTAC networks, mobile station 700 is registered on 

the network using a unique identification number associated 

with each mobile station. In UMTS and GPRS networks, 

however, network access is associated with a Subscriber or user of mobile Station 700. A GPRS mobile Station therefore 

requires a subscriber identity module (SIM) card in order to 

operate on a GPRS network. Without a valid SIM card, a 

GPRS mobile station will not be fully functional. Local or 

non-network communication functions, as well as legally required functions (if any) Such as "911" emergency calling, 

may be available, but mobile station 700 will be unable to 

carry out any other functions involving communications over 

the network 702. The SIM interface 744 is normally similar to 

a card-slot into which a SIM card can be inserted and ejected like a diskette or PCMCIA card. The SIM card can have 

approximately 64K of memory and hold many key configu 

ration 751, and other information 753 such as identification, 

and subscriber related information. 

When required network registration or activation proce 

dures have been completed, mobile station 700 may send and 

receive communication signals over the network 702. Signals received by antenna 716 through communication network 

702 are input to receiver 712, which may perform such com 

mon receiver functions as signal amplification, frequency 

down conversion, filtering, channel selection and the like, and 

in the example system shown in FIG. 7, analog to digital (NO) 

conversion. NO conversion of a received signal allows more 

complex communication functions such as demodulation and 

decoding to be performed in the DSP720. In a similar man 

ner, signals to be transmitted are processed, including modu 

lation and encoding for example, by DSP 720 and input to 

transmitter 714 for digital to analog conversion, frequency up 

conversion, filtering, amplification and transmission over the 

communication network 702 via antenna 718. DSP 720 not 

only processes communication signals, but also provides for 

receiver and transmitter control. For example, the gains 

applied to communication signals in receiver 712 and trans 

mitter 714 may be adaptively controlled through automatic 

gain control algorithms implemented in DSP 720. 

Mobile station 700 preferably includes a microprocessor 

738 which controls the overall operation of the device. Com 

munication functions, including at least data and Voice com 

munications, are performed through communication Sub 

system 711. Microprocessor 738 also interacts with further 

device subsystems such as the display 722, flash memory 724, 

random access memory (RAM) 726, auxiliary input/output 

(I/O) subsystems 728, serial port 730, keyboard 732, speaker 

Case 1:20-cv-22051-JEM Document 1-14 Entered on FLSD Docket 05/15/2020 Page 12 of 16
US 8,600,383 B2 

734, microphone 736, a short-range communications sub 

system 740 and any other device subsystems generally des 

ignated as 742. 

Some of the subsystems shown in FIG.5 perform commu 

nication-related functions, whereas other Subsystems may 

provide “resident' or on-device functions. Notably, some 

subsystems, such as keyboard 732 and display 722, for 

example, may be used for both communication-related func 

tions, such as entering a text message for transmission over a 

communication network, and device-resident functions such as a calculator or task list. 

Operating system software used by the microprocessor 738 

is preferably stored in a persistent store Such as flash memory 

724, which may instead be a read-only memory (ROM) or 

similar storage element (not shown). Those skilled in the art 

will appreciate that the operating system, specific device 

applications, or parts thereof, may be temporarily loaded into 

a volatile memory such as RAM 726. Received communica 

tion signals may also be stored in RAM 726. 

As shown, flash memory 724 can be segregated into dif 

ferent areas for both computer programs 758 and program 

data storage 750, 752, 754 and 756. These different storage 

types indicate that each program can allocate a portion of 

flash memory 724 for their own data storage requirements. 

Microprocessor 738, in addition to its operating system func 

tions, preferably enables execution of software applications 

on the mobile station. A predetermined set of applications that 

control basic operations, including at least data and Voice 

communication applications for example, will normally be 

installed on mobile station 700 during manufacturing. A pre 

ferred software application may be a personal information 

manager (PIM) application having the ability to organize and 

manage data items relating to the user of the mobile station 

Such as, but not limited to, e-mail, calendar events, Voice 

mails, appointments, and task items. Naturally, one or more 

memory stores would be available on the mobile station to 

facilitate storage of PIM data items. Such PIM application 

would preferably have the ability to send and receive data 

items, via the wireless network 702. In a preferred embodi 

ment, the PIM data items are seamlessly integrated, synchro 

nized and updated, via the wireless network 702, with the 

mobile station user's corresponding data items stored or asso 

ciated with a host computer system. Further applications may 

also be loaded onto the mobile station 700 through the net 

work 702, an auxiliary I/O subsystem 728, serial port 730, 

short-range communications subsystem 740 or any other Suit 

able subsystem 742, and installed by a user in the RAM 726 

or preferably a non-volatile store (not shown) for execution 

by the microprocessor 738. Such flexibility in application 

installation increases the functionality of the device and may 

provide enhanced on-device functions, communication-re 

lated functions, or both. For example, secure communication 

applications may enable electronic commerce functions and 

other such financial transactions to be performed using the 

mobile Station 700. 

In a data communication mode, a received signal Such as a 

text message or web page download will be processed by the 

communication Subsystem 711 and input to the microproces 

sor 738, which preferably further processes the received sig 

nal for output to the display 722, or alternatively to an auxil 

iary I/O device 728. A user of mobile station 700 may also 

compose data items such as email messages for example, using the keyboard 732, which is preferably a complete alphanumeric keyboard or telephone-type keypad, in con 

junction with the display 722 and possibly an auxiliary I/O 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

10 

device 728. Such composed items may then be transmitted 

over a communication network through the communication 

subsystem 711. 

For Voice communications, overall operation of mobile 

station 700 is similar, except that received signals would 

preferably be output to a speaker 734 and signals for trans 

mission would be generated by a microphone 736. Alterna 

tive Voice or audio I/O Subsystems, such as a voice message recording Subsystem, may also be implemented on mobile 

station 700. Although voice or audio signal output is prefer ably accomplished primarily through the speaker 734, dis 

play 722 may also be used to provide an indication of the 

identity of a calling party, the duration of a voice call, or other 

voice call related information for example. Serial port 730 in FIG. 5, would normally be implemented in a personal digital assistant (PDA)-type mobile station for 

which synchronization with a user's desktop computer (not 

shown) may be desirable, but is an optional device compo 

nent. Such a port 730 would enable a user to set preferences 

through an external device or software application and would 

extend the capabilities of mobile station 700 by providing for 

information or software downloads to mobile station 700 

other than through a wireless communication network. The 

alternate download path may for example be used to load an 

encryption key onto the device through a direct and thus 

reliable and trusted connection to thereby enable secure 

device communication. 

Other communications subsystems 740, such as a short 

range communications Subsystem, is a further optional com 

ponent which may provide for communication between 

mobile station 700 and different systems or devices, which 

need not necessarily be similar devices. For example, the 

subsystem 740 may include an infrared device and associated 

circuits and components or a BluetoothTM communication 

module to provide for communication with similarly enabled 

systems and devices. 

EXTENSIONS AND ALTERNATIVES 

In the foregoing specification, the invention has been 

described with reference to specific embodiments thereof. It 

will, however, be evident that various modifications and 

changes may be made thereto without departing from the 

Scope of the technique. The specification and drawings are, 

accordingly, to be regarded in an illustrative rather than a 

restrictive sense. 

It is to be noted that the methods as described have shown 

steps being carried outina particular order. However, it would 

be clear to a person skilled in the art that the order of some of 

the steps may be immaterial with respect to the operation of 

the method. The ordering of the steps as described herein is 

not intended to be limiting. 

It is also to be noted that where a method has been 

described it is intended that protection is also sought for a 

device arranged to carry out the method and where features 

have been claimed independently of each other these may be 

used together with other claimed features. 

The invention claimed is: 

1. A method of cell reselection by a user equipment device 

(UE), the UE operable with a first cellular Radio Access 

Technology (RAT) and a second cellular RAT, the method 

comprising: 

when the UE is camped on a cell of the first RAT, deter 

mining whether a cell of a second RAT is suitable for 

camping, 

the UE not considering said cell of the second RAT as a 

candidate for reselection if said cell of the second RAT is 

Case 1:20-cv-22051-JEM Document 1-14 Entered on FLSD Docket 05/15/2020 Page 13 of 16
US 8,600,383 B2 

11 

not suitable for camping, and further not considering 

said cell of the second RAT for a time period. 

2. The method according to claim 1, further comprising 

considering said cell of the second RAT as a candidate for 

reselection after expiry of the time period. 

3. The method according to claim 1, wherein not consid 

ering said cell of the second RAT comprises removing said 

cell from a list of neighboring cells. 

4. The method according to claim 1, wherein not consid 

ering said cell of the second RAT comprises flagging said cell 

in a list of neighboring cells as being unsuitable for camping. 

5. The method according to claim 1, wherein said cell of the 

second RAT is not suitable when it is barred. 

6. The method according to claim 1, wherein said cell of the 

second RAT is not suitable due to being part of a list of barred 

cells. 

7. The method according to claim 1, wherein said cell of the 

second RAT is not suitable due to being part of a list of 

unsuitable cells. 

8. The method according to claim 1, wherein said cell of the 

second RAT is not suitable due to belonging to a public land 

mobile network (PLMN) that is not the same as a PLMN 

selected by the UE. 

9. The method according to claim 1, wherein the time 

period is a maximum of 300 seconds. 

10. The method according to claim 1, wherein the time 

period is 300 seconds. 

11. The method according to claim 1, wherein the time 

period is a defined period of time. 

12. The method according to claim 1, wherein the time 

period is a limited period of time. 

13. The method according to claim 1, wherein the UE 

receives a list of neighboring cells including the cell of the 

second RAT. 

14. The method of claim 1, wherein the first RAT is 

selected from a group including UMTS, GSM, or CDMA; 

and the second RAT is different from the first RAT and 

selected from the group including UMTS, GSM, or CDMA. 

15. The method of claim 1, wherein the reselection is for 

camping. 

16. The method of claim 1, wherein determining whether a 

cell of a second RAT is Suitable for camping comprises: generating measurement data for cells in a neighboring cell 

list; 

identifying from the measurement data a cell that meets a 

cell reselection criterion; and 

determining whether the identified cell is suitable for 

camping when the identified cell is a cell of the second 

RAT. 

17. A user equipment device (UE) configured to be oper 

able with a first cellular Radio Access Technology (RAT) and 

a second cellular RAT, the UE comprising: 

a processor and memory, the UE being operable so that, 

when the UE is camped on a cell of the first RAT, it is 

determined whether a cellofa second RAT is suitable for 

camping, 

wherein the UE does not consider said cell of the second 

RAT as a candidate for reselection if said cell of the 

second RAT is not suitable for camping, and further does 

not consider said cell of the second RAT for a time 

period. 

18. The UE according to claim 17, further configured to 

consider said cell of the second RAT as a candidate for rese 

lection after expiry of the time period. 

19. The UE according to claim 17, wherein, in order to not 

consider said cell of the second RAT, the UE is configured to 

remove said cell from a list of neighboring cells. 

5 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

12 

20. The UE according to claim 17, wherein, in order to not 

consider said cell of the second RAT, the UE is arranged to 

flag said cell in a list of neighboring cells as being unsuitable 

for selection. 

21. The UE according to claim 17, wherein said cell of a 

second RAT is not suitable when it is barred. 

22. The UE according to claim 17, wherein said cell of a 

second RAT is not suitable due to being part of a list of barred 

cells. 

23. The UE according to claim 17, wherein said cell of a 

second RAT is not suitable due to being part of a list of 

unsuitable cells. 

24. The UE according to claim 17, wherein said cell of a 

second RAT is not suitable due to belonging to a public land 

mobile network (PLMN) that is not to the same as a PLMN 

selected by the UE. 

25. The UEaccording to claim 17, wherein the time period 

is a maximum of 300 seconds. 

26. The UEaccording to claim 17, wherein the time period 

is 300 seconds. 

27. The UEaccording to claim 17, wherein the time period 

is a defined period of time. 

28. The UE according to claim 17, further configured to 

receive a list of neighboring cells including the cell of the 

second RAT. 

29. The UE of claim 17, wherein the first RAT is selected 

from a group including UMTS, GSM, GPRS or CDMA; and 

the second RAT is different from the first RAT and selected 

from the group including UMTS, GSM, GPRS, or CDMA. 

30. The UE of claim 17, wherein the reselection is for 

camping. 

31. The UE of claim 17, further operable to: 

generate measurement data for cells in a neighboring cell 

list; 

identify from the measurement data a cell that meets a cell 

reselection criterion; and 

determine whether the identified cell is suitable for camp ing when the identified cell is a cell of the second RAT. 

32. A method of cell reselection by a user equipment device 

(UE), the UE operable with a first cellular Radio Access 

Technology (RAT) and a second cellular RAT, the method 

comprising: 

when the UE is camped on a cell of the first RAT, 

the UE considering a cell of a second RAT as barred as a 

candidate for reselection for a time period if said cell of 

the second RAT is not suitable for camping. 33. The method according to claim 32, further comprising 

determining whether said cell of the second RAT is suitable 

for camping. 

34. The method according to claim 32, further comprising 

considering said cell of the second RAT as a candidate for 

reselection after expiry of the time period. 

35. The method according to claim 32, wherein consider 

ing said cell of the second RAT as barred comprises removing 

said cell from a list of neighboring cells. 

36. The method according to claim 32, wherein consider 

ing said cell of the second RAT as barred comprises flagging 

said cell in a list of neighboring cells as being unsuitable for 

camping. 

37. The method according to claim 32, wherein said cell of 

the second RAT is not suitable when it is barred. 

38. The method according to claim 32, wherein said cell of 

the second RAT is not suitable due to being part of a list of 

barred cells. 

39. The method according to claim 32, wherein said cell of 

the second RAT is not suitable due to being part of a list of 

unsuitable cells. 

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US 8,600,383 B2 

13 

40. The method according to claim 32, wherein said cell of 

the second RAT is not suitable due to belonging to a public 

land mobile network (PLMN) that is not the same as a PLMN 

selected by the UE. 

41. The method according to claim 32, wherein the time 

period is a maximum of 300 seconds. 

42. The method according to claim 32, wherein the time 

period is 300 seconds. 

43. The method according to claim 32, wherein the time 

period is a defined period of time. 

44. The method according to claim 32, wherein the time 

period is a limited period of time. 

45. The method according to claim 32, wherein the UE 

receives a list of neighboring cells including the cell of the 

second RAT. 

46. The method of claim 32, wherein the first RAT is 

selected from a group including UMTS, GSM, or CDMA; 

and the second RAT is different from the first RAT and 

selected from the group including UMTS, GSM, or CDMA. 

47. The method of claim 32, wherein the reselection is for 

camping. 

48. The method of claim 32, further comprising: generating measurement data for the cells in a neighboring 

cell list; 

identifying from the measurement data a cell that meets a 

cell reselection criterion; and 

determining whether the identified cell is suitable for 

camping when the identified cell is a cell of the second 

RAT. 

49. A user equipment device (UE) configured to be oper 

able with a first cellular Radio Access Technology (RAT) and 

a second cellular RAT, the UE comprising: 

a processor and memory, the UE being operable so that, 

when the UE is camped on a cell of the first RAT, 

the UE considers a cell of a second RAT as barred as a 

candidate for reselection for a time period if said cell of 

the second RAT is not suitable for camping. 

50. The UE according to claim 49, wherein the UE is 

configured to determine whether said cell of the second RAT 

is suitable for camping. 

51. The UE according to claim 49, further configured to 

consider said cell of the second RAT as a candidate for rese 

lection after expiry of the time period. 

52. The UE according to claim 49, wherein, in order to 

consider said cell of the second RAT as barred, the UE is 

configured to remove said cell from a list of neighboring cells. 

53. The UE according to claim 49, wherein, in order to 

consider said cell of the second RAT as barred, the UE is 

arranged to flag said cell in a list of neighboring cells as being 

unsuitable for camping. 

54. The UE according to claim 49, wherein said cell of the 

second RAT is not suitable when it is barred. 

55. The UE according to claim 49, wherein said cell of the 

second RAT is not suitable due to being part of a list of barred 

cells. 

56. The UE according to claim 49, wherein said cell of the 

second RAT is not suitable due to being part of a list of 

unsuitable cells. 

57. The UE according to claim 49, wherein said cell of the 

second RAT is not suitable due to belonging to a public land 

mobile network (PLMN) that is not the same as a PLMN 

selected by the UE. 

58. The UE according to claim 49, wherein the time period 

is a maximum of 300 seconds. 

59. The UE according to claim 49, wherein the time period 

is 300 seconds. 

10 

15 

25 

30 

35 

40 

45 

50 

55 

60 

65 

14 

60. The UE according to claim 49, wherein the time period 

is a defined period of time. 

61. The UE according to claim 49, wherein the time period 

is a limited period of time. 

62. The UE according to claim 49, further configured to 

receive a list of neighboring cells including the cell of the 

second RAT. 

63. The UE of claim 49, wherein the first RAT is selected 

from a group including UMTS, GSM, or CDMA; and the 

second RAT is different from the first RAT and selected from 

the group including UMTS, GSM, or CDMA. 

64. The UE of claim 49, wherein the reselection is for 

camping. 

65. The UE of claim 49, further operable to: 

generate measurement data for the cells in a neighboring 

cell list; 

identify from the measurement data a cell that meets a cell 

reselection criterion; and 

determine whether the identified cell is suitable for camp 

ing when the identified cell is a cell of the second RAT. 

66. A method of cell reselection by a user equipment device 

(UE), the UE operable with a first cellular Radio Access 

Technology (RAT) and a second cellular RAT, the method 

comprising: 

when the UE is camped on a cell of the first RAT, 

determining whether a cell of a second RAT is suitable for 

camping, 

the UE excluding said cell of the second RAT as a candi 

date for reselection for a time period if said cell of the 

second RAT is not suitable for camping. 

67. The method according to claim 66, further comprising 

considering said cell of the second RAT as a candidate for 

reselection after expiry of the time period. 

68. The method according to claim 66, wherein excluding 

said cell of the second RAT comprises removing said cell 

from a list of neighboring cells. 

69. The method according to claim 66, wherein excluding 

said cell of the second RAT comprises flagging said cell in a 

list of neighboring cells as being unsuitable for camping. 

70. The method according to claim 66, wherein said cell of 

the second RAT is not suitable when it is barred. 

71. The method according to claim 66, wherein said cell of 

the second RAT is not suitable due to being part of a list of 

barred cells. 

72. The method according to claim 66, wherein said cell of 

the second RAT is not suitable due to being part of a list of 

unsuitable cells. 

73. The method according to claim 66, wherein said cell of 

the second RAT is not suitable due to belonging to a public 

land mobile network (PLMN) that is not the same as a PLMN 

selected by the UE. 

74. The method according to claim 66, wherein the time 

period is a maximum of 300 seconds. 

75. The method according to claim 66, wherein the time 

period is 300 seconds. 

76. The method according to claim 66, wherein the time 

period is a defined period of time. 

77. The method according to claim 66, wherein the time 

period is a limited period of time. 

78. The method according to claim 66, wherein the UE 

receives a list of neighboring cells including the cell of the 

second RAT. 

79. The method of claim 66, wherein the first RAT is 

selected from a group including UMTS, GSM, or CDMA; 

and the second RAT is different from the first RAT and 

selected from the group including UMTS, GSM, or CDMA. 

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15 

80. The method of claim 66, wherein the reselection is for 

camping. 

81. The method of claim 66, wherein determining whether 

a cell of a second RAT is Suitable for camping comprises: 

generating measurement data for cells in a neighboring cell 

list; 

identifying from the measurement data a cell that meets a 

cell camping criterion; and 

determining whether the identified cell is suitable for 

camping when the identified cell is a cell of the second 

RAT. 

82. A user equipment device (UE) configured to be oper 

able with a first cellular Radio Access Technology (RAT) and 

a second cellular RAT, the UE comprising: 

a processor and memory, the UE being operable so that, 

when the UE is camped on a cell of the first RAT, it is 

determined whether a cellofa second RAT is suitable for 

camping, 

wherein the UE excludes said cell of the second RAT as a 

candidate for reselection for a time period if said cell of 

the second RAT is not suitable for camping. 

83. The UE according to claim 82, further configured to 

consider said cell of the second RAT as a candidate for rese 

lection after expiry of the time period. 

84. The UE according to claim 82, wherein, in order to 

exclude said cell of the second RAT, the UE is configured to 

remove said cell from a list of neighboring cells. 

85. The UE according to claim 82, wherein, in order to 

exclude said cell of the second RAT, the UE is arranged to flag said cell in a list of neighboring cells as being unsuitable for 

camping. 

86. The UE according to claim 82, wherein said cell of the 

second RAT is not suitable when it is barred. 

10 

15 

25 

30 

16 

87. The UE according to claim 82, wherein said cell of the 

second RAT is not suitable due to being part of a list of barred 

cells. 

88. The UE according to claim 82, wherein said cell of the 

second RAT is not suitable due to being part of a list of 

unsuitable cells. 

89. The UE according to claim 82, wherein said cell of the 

second RAT is not suitable due to belonging to a public land 

mobile network (PLMN) that is not the same as a PLMN 

selected by the UE. 

90. The UEaccording to claim 82, wherein the time period is a maximum of 300 seconds. 

91. The UEaccording to claim 82, wherein the time period is 300 seconds. 

92. The UEaccording to claim 82, wherein the time period is a defined period of time. 

93. The UEaccording to claim 82, wherein the time period is a limited period of time. 

94. The UE according to claim 82, further configured to 

receive a list of neighboring cells including the cell of the 

second RAT. 

95. The UE of claim 82, wherein the first RAT is selected 

from a group including UMTS, GSM, or CDMA; and the 

second RAT is different from the first RAT and selected from 

the group including UMTS, GSM, or CDMA. 

96. The UE of claim 82, wherein the reselection is for 

camping. 

97. The UE of claim 82, further operable to: 

generate measurement data for cells in a neighboring cell 

list; 

identify from the measurement data a cell that meets a cell 

reselection criterion; and 

determine whether the identified cell is suitable for camp 

ing when the identified cell is a cell of the second RAT. k k k k k 

Case 1:20-cv-22051-JEM Document 1-14 Entered on FLSD Docket 05/15/2020 Page 16 of 16