Table 2 GSM, UMTS and LTE Coverage Levels

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1 6 INDICATORS OF QUALITY OF SERVICE This sectio defies quality idicators that characterize the performace of services supported o mobile commuicatio systems i their various phases of access ad use RADIO COVERAGE RADIO NETWORK AVAILABILITY Network availability is the probability that mobile services are available to a user, via a radio ifrastructure (etwork radio coverage). Radio Network Availability [%] = Measuremets with Available Mobile Services Measuremets Coducted 100 (6.1.1) Mobile services are cosidered to be available whe radio sigal levels show values above the miimum thresholds that allow their use. These thresholds may be adjusted by mobile operators ad usually preset differet values for GSM, UMTS ad LTE. As appropriate measuremet equipmet - RF Scaer -, combied with a geo-referecig system makes it possible to obtai coverage levels of mobile etworks o the routes uder study. Table 2 GSM, UMTS ad LTE Coverage Levels Coverage GSM UMTS LTE Very good 75 dbm RxLev 85 dbm CPICH RSCP 95 dbm RSRP Good 85 dbm RxLev 75 dbm 95 dbm CPICH RSCP 85 dbm 105 dbm RSRP 95 dbm Acceptable 95 dbm RxLev 85 dbm 105 dbm CPICH RSCP 95 dbm 115 dbm RSRP 105 dbm Poor 105 dbm RxLev 95 dbm 115 dbm CPICH RSCP 105 dbm 125 dbm RSRP 115 dbm No-existet RxLev 105 dbm CPICH RSCP 115 dbm RSRP 125 dbm 6 These Service Quality Idicators are based o the followig techical specificatios: ETSI TS , amely part 2, ETSI TR , ETSI TR , ETSI TR , ETSI TR , ETSI EG , amely parts 3 ad 4, ETSI TS , ETSI TS , ETSI TS , ETSI TS , ETSI TS , ETSI TS ; o the followig recommedatios ITU-T P.863, ITU-T P.863.1, ITU-T J.343, ITU-T J.343.1, ITU-T P.910 ad ITU-T Q.3960; ad o the followig reports ECC Report 256 ad ECC Report 103 [ETSI TS , ETSI TR , ETSI TR , ETSI TR , ETSI TR , ETSI EG , ETSI EG , ETSI TS , ETSI TS , ETSI TS , ETSI TS , ETSI TS , ETSI TS , ITU-T P.863, ITU-T P.863.1, ITU-T J.343, ITU-T J.343.1, ITU-T P.910, ITU-T Q.3960, ECC Report 256, ECC Report 103]. Methodology for Assessig the Performace of Mobile Networks ad Services 29

2 6.2 VOICE SERVICE ACCESSIBILITY OF THE VOICE SERVICE Service accessibility is the probability that the ed-user ca access the voice service, that is, the probability of beig successful whe makig calls. A call is cosidered to be Set Up with Success if it reaches the called termial (a call sigal is heard o the caller termial). Service accessibility [%] = Sucessfully Set Up Calls Attempts to Set Up Calls 100 (6.2.1) VOICE CALL SET UP TIME Call set up time is the period of time elapsig from the sedig of a complete destiatio address (target telephoe umber) to the settig up of a call. Call Set up time [s] = t callig sigal t address sedig taddress sedig momet whe the user presses the sed butto. tcallig sigal momet whe the call is successfully set up (oe hears the call sigal o the caller termial). (6.2.2) VOICE CALL COMPLETION RATE The voice call completio rate is the probability that a call has, after beig successfully set up, to be maitaied durig a period of time, edig ormally, that is, accordig to the user s will. Call Completio Rate [%] = Normally eded calls Sucessfully Set Up Calls 100 (6.2.3) VOICE CALL AUDIO QUALITY This idicator quatifies the perceptibility of the coversatio durig a voice call. Both commuicatio 30 GSM-UMTS-LTE Jue 2017

3 directios are assessed ad oly calls edig ormally are cosidered. The assessmet of this QoS idicator cosists i the compariso betwee the origial audio sample that is set, X(t), ad the correspodig received degraded sample, Y(t), o the other ed of the call, by applyig the POLQA algorithm 7. The objective audio quality idex obtaied through this algorithm is close to what would be obtaied if sample Y(t) were submitted to the subjective appreciatio of a pael of service users. Call Audio Quality side A [MOS LQO ] = f{x B (t) ; Y A (t)} Call Audio Quality side B [MOS LQO ] = f{x A (t) ; Y B (t)} side A; side B desigatio of both eds of a voice call. MOSLQO scale that measures the perceived audio quality (Mea Opiio Score Listeig-oly Quality Objective). f fuctio correspodig to the applicatio of a calculatio algorithm ad coversio fuctio of results i MOSLQO values. XA(t); XB(t) origial audio sample set by side A (B). YA(t); YB(t) degraded audio sample received by side A (B), resultig from the trasmissio of the origial sample XB(t) (XA(t)). (6.2.4) Results obtaied by the applicatio of the algorithm are show o a MOS (Mea Opiio Score) type scale ragig from 1 to 5 called MOS_LQO (Mea Opiio Score Listeig-oly Quality Objective), such as show o Table 3. The MOS scale quatifies the effort that it takes to perceive a commuicatio. Table 3 - MOSLQO Scale MOS Quality 5 Excellet 4 Good 3 Acceptable 2 Poor 1 Bad I situatios where each directio of the same call seds ad receives several ( ) audio samples {X1(t), X2(t),, X(t); Y1(t), Y2(t),, Y(t)}, the Call Audio Quality idicator is calculated through the arithmetic average of values obtaied by applyig the formula show above to each pair of audio samples, that is: 7 POLQA Perceptual Objective Listeig Quality Assessmet [ITU-T P.863, ITU-T P.863.1]. Methodology for Assessig the Performace of Mobile Networks ad Services 31

4 Call Audio Quality side A [MOS LQO ] = Call Audio Quality side B [MOS LQO ] = i=1 i=1 f{x i B (t) ; Y ia (t)} f{x i A (t) ; Y ib (t)} (6.2.5) 6.3 SMS SHORT MESSAGE SERVICE ACCESSIBILITY OF THE SMS SERVICE Service accessibility is the probability that the user ca access the Short Message Service, that is, the probability of beig successful whe sedig SMS. Accessibilityof the SMS Service [%] = Successfully Set SMS Attempts to Sed SMS 100 (6.3.1) SMS DELIVERY TIME The SMS delivery time correspods to the time betwee the begiig of the sedig of the message to a Short Message Cetre (SMSC) ad the ed of its receptio at the destiatio termial equipmet. SMS Delivery Time [s] = t ed_receptio t start_sedig tstart_sedig momet whe the user starts sedig the SMS. ted_receptio momet whe the destiatio termial equipmet eds receptio of the SMS set by the origiatio termial equipmet (6.3.2) Corrupted messages, messages delivered outside the predefied time frame ad duplicate received messages are ot take ito cosideratio i the calculatio of this idicator. A SMS is cosidered to be corrupted where there is at least oe-bit error SMS DELIVERY RATE The SMS delivery rate is the probability that the message is delivered successfully to the destiatio, that 32 GSM-UMTS-LTE Jue 2017

5 is, the ratio betwee the umber of SMS received successfully by the destiatio termial equipmet ad the umber of SMS set by the origiatio termial equipmet. SMS delivery rate [%] = Successfully Received SMS Attempts to Sed SMS 100 (6.3.3) Corrupted messages or messages delivered outside the predefied time frame are cosidered to have failed for the purpose of the calculatio of this idicator. A SMS is cosidered to be corrupted where there is at least oe-bit error. Duplicate received messages are ot accouted for i this idicator. 6.4 DATA SERVICES COMPLETED DATA SESSION RATE (HTTP, HTTP WEB BROWSING AND YOUTUBE VIDEO STREAMING) Probability that a data sessio (File Trasfer - HTTP upload/dowload, Iteret browsig HTTP web browsig or YouTube Video Streamig) is set up ad takes place successfully, that is, where it remais active durig the full period of time predefied for the file trasfer (HTTP upload/dowload), where it allows the full trasfer of the webpage (HTTP web browsig) or where it allows the trasfer ad full playout of multimedia cotet (YouTube Video Streamig). Completed Data Sessio Ratio [%] = Successfully Completed Sessios Attempts to Set Up Sessios 100 (6.4.1) DATA TRANSFER RATE (HTTP) This idicator quatifies the average data trasfer rate durig a File Trasfer sessio (HTTP upload/dowload). This idicator oly takes accout of successfully completed sessios (sessios that remaied active durig the full period of time predefied to trasfer the file). Methodology for Assessig the Performace of Mobile Networks ad Services 33

6 Volume of Data Set or Received [kbit] Data Trasfer Rate [kbps] = Sedig or Receptio Time [s] Sedig or Receptio Time Predefied period of time required to sed or receive the iformatio. Does ot iclude the period of time required to set up data sessios (phases of packet switched etwork registratio, PDP cotext activatio (for GSM/UMTS) or Dedicated EPS Bearer Setup (for LTE) ad remote server autheticatio). (6.4.2) WEBPAGE TRANSFER TIME (HTTP WEB BROWSING) This idicator quatifies the average time required for the trasfer of a webpage (referece page or aother). This idicator oly takes accout of successfully completed sessios (sessios that allowed the full trasfer of the webpage). Webpage Trasfer Time [s] = t ed_receptio t webpage_request Twebpage_request momet whe the user equipmet makes the webpage receptio request. Ted_receptio momet whe the full webpage is received by the user equipmet. (6.4.3) CONTENT DISPLAY DELAY (YOUTUBE VIDEO STREAMING) The Cotet Display Delay withi a YouTube Video Streamig sessio is the period of time betwee the request for multimedia cotets (the user presses play ) ad the start of video playout (display of the first frame) i the termial equipmet of the user. Cotet Display Delay [s] = t start of playout t cotet request Tcotet request momet whe the user makes the request for cotets. Tstart of playout momet whe the playout of cotets requested start i the user equipmet. (6.4.4) FREEZE DURATION (YOUTUBE VIDEO STREAMING) This idicator aggregates all iterruptios or freezig evets durig a YouTube Video Streamig sessio 34 GSM-UMTS-LTE Jue 2017

7 that eds ormally. Freezes are oly cosidered where they are recogized by the user (where they exceed 120 ms [ETSI TR ]). Freeze Duratio [s] = i=0 (Freeze Duratio) i [s] total umber of freezes durig a sessio (6.4.5) VIDEO QUALITY (YOUTUBE VIDEO STREAMING) This idicator quatifies the visual quality of the commuicatio durig the YouTube Video Streamig sessio. Oly sessios that are ormally completed are cosidered. The video quality is estimated through the algorithm defied by ITU i its Recommedatio J [ITU- T J.343.1]. This algorithm is based o a o-referece 8 model (Hybrid-NRe hybrid o-referece ecrypted), that is, the video quality is estimated via aalysis of the received video, the video origially trasmitted ot beig kow. Figure 3 Block-diagram of the Hybrid-NRe model [ITU-T J.343.1]. The Hybrid-NRe model measures the visual effect of spatial ad temporal degradatios as a result of video codig, erroeous trasmissio or video rescalig. The visual quality estimated by this model is preseted o a MOS (Mea Opiio Score) scale, ragig from 1 to 5, derived from the ACR (absolute category ratig) scale defied by ITU i Recommedatio 8 The use of a o-referece model allows for tests with ay public cotet available o YouTube to be coducted. Methodology for Assessig the Performace of Mobile Networks ad Services 35

8 P.910 [ITU-T P910], preseted i Table 4. Table 4 - MOS Scale [ITU-T P.910] MOS Quality 5 Excellet 4 Good 3 Acceptable 2 Poor 1 Bad VIDEO STREAMING RESOLUTION (YOUTUBE VIDEO STREAMING) I a YouTube Video Streamig sessio, the YouTube allows the dyamic adjustmet of the video resolutio of trasmitted cotets, optimizig it to the available badwidth ad characteristics of the mobile termial, ad improvig the viewig experiece. Oly sessios that are ormally completed are cosidered. Video streamig resolutio [p] = i=1 (Video clip resolutio) i [p] total umber of video clips that make up the cotets received i the mobile termial equipmet (6.4.6) DATA TRANSFER LATENCY This idicator quatifies the time required for a iformatio packet to be delivered from the user equipmet to the Dedicated Server or vice-versa. This delay correspods to half the Roud Trip Time (RTT) obtaied by the Pig tool (ICMP echo). Data Trasfer Latecy [ms] = Pig RTT[ms] 2 (6.4.7) 36 GSM-UMTS-LTE Jue 2017