smartphone impact

1 © Nokia Siemens Networks Telefonica Colombia MBB assessment / Impact of smartphones / May 2010

Impact of Smartphones in Telefonica Colombia networkMobile Broadband assessment project, May 2010Version 1

2 © Nokia Siemens Networks - confidential MBB Solution presentation / May 20All rights reserved

Content

• What's the problem?• What is a "Smartphone"• Smartphone penetration in TeM Colombia• Signalling and data load• Impact from Smartphones and possible optimization actions


What's the problem?

• The new smart phones such as G1, Blackberry, iPhone and N97 are loading the network in a new way

• People are using always on applications such as IM and email a lot with the smart phones – ”Always on” applications rely on keep alive messages

• In addition to keep alive messages these always on applications send lot of small data packages

• In Smart phone dominated network changes can happen overnight, caused by new firmware or killer application

• For example iPhone user-friendly firmware upgrade makes upgrades unheard fast: in one network 50% of phones were upgraded within 1 week after the new FW came available – boosting the impact of new firmware


What is a Smartphone?

• Smartphones thus behave differently from modems or handsets aimed at pure telephony

• For the purposes of this analysis, the UEs used in the Telefonica Colombia network have been split into– 3G modems (dongles) intended for providing broadband access to computers– iPhones– Blackberry – Other smartphones– Ordinary handsets

• The table on the next slide shows the categorization of the most used UE models

• Note that the categorization is purely based on the IMEI– For example a Nokia N95 used as a modem is categorized as "Handset", not as

"Modem"– For example an iPhone without any always-on applications, purely used for telephony,

is categorized as "iPhone", not as "Handset"• Especially the borderline between "Handset" and "Smartphone" is blurry and

subjective, so other statistics may have another categorization


What is a Smartphone?Marketing Name Manufacturer Category Marketing Name Manufacturer Category9000 Research in Motion (RIM) Blackberry E156B Huawei Technologies Co Ltd Modem8100 Black Research in Motion (RIM) Blackberry ALCATEL One Touch X060A TCT Mobile Suzhou Limited Modem9700 Research in Motion (RIM) Blackberry MD300 Sony Ericsson Mobile Communications AB ModemPearl 8100 Research in Motion (RIM) Blackberry E160 Huawei Technologies Co Ltd Modem8100 Pearl Sunset Research in Motion (RIM) Blackberry Huawei E226 Huawei Technologies Co Ltd Modem8320 Research in Motion (RIM) Blackberry MF626 ZTE Corporation Modem8220 (TMO US) Research in Motion (RIM) Blackberry E968 Huawei Technologies Co Ltd Modem8100 Research in Motion (RIM) Blackberry E166 Huawei Technologies Co Ltd Modem8310 Research in Motion (RIM) Blackberry IdeaPad S10-2 Lenovo Mobile Communication Technology Ltd ModemBlackBerry 8100 Research in Motion (RIM) Blackberry F3507g Ericsson AB Modem8900 Research in Motion (RIM) Blackberry E800 Huawei Technologies Co Ltd ModemR6231GE / 6230 Research in Motion Ltd Blackberry E176 Huawei Technologies Co Ltd Modem8310 Titanium Research in Motion (RIM) Blackberry MF110 ZTE Corporation Modem9700 (AT&T) Research in Motion (RIM) Blackberry MF622 ZTE Corporation Modem9000 (AT&T) Research in Motion (RIM) Blackberry ZTE MF100 ZTE Corporation ModemC510a Sony Ericsson Mobile Communications AB Handset MC8775V SierraWireless ModemNokia 3120c-1b Nokia Corporation Handset One Touch X030 TCT Mobile Suzhou Limited Modem6120c-1 Nokia Corporation Handset E1756 Huawei Technologies Co Ltd ModemN95-3 Nokia Corporation Handset E1556 Huawei Technologies Co Ltd ModemN95-4 Nokia Corporation Handset MF100 ZTE Corporation ModemE51-1 Nokia Corporation Handset E63-2 Nokia Corporation SmartphoneNokia N78-3 Nokia Corporation Handset E71-2 Nokia Corporation SmartphoneNokia 5610d-1b Nokia Corporation Handset 5800d-1b Nokia Corporation Smartphone3120c-1b Nokia Corporation Handset SGH-i637 Samsung Korea SmartphoneNokia 5610 XpressMusic Nokia Corporation Handset U7515/U7510-5/HUAWEI U7510-5 Huawei Technologies Co Ltd SmartphoneNokia 6500 Slide Nokia Corporation Handset SGH-A797 Samsung Korea SmartphoneNokia 3120c-1c Nokia Corporation Handset N97-3 Nokia Corporation SmartphoneSGH-A737 Samsung Korea Handset MRQ6-334411A11 Motorola Inc. SmartphoneW760 Sony Ericsson Mobile Communications AB Handset Treo 750na Palm SmartphoneSGH-A736 Samsung Korea Handset E71x Nokia Corporation Smartphone5320d-1b Nokia Corporation Handset E75-2 Nokia Corporation SmartphoneW760i/a Sony Ericsson Mobile Communications AB Handset X1a Sony Ericsson Mobile Communications AB SmartphoneNokia 6500s-1 Nokia Corporation Handset DIAM110 HTC Corp SmartphoneMQ4-4411H11 Motorola Inc. Handset SGH-i900L Samsung Korea SmartphoneCU400 LG Electronics Handset SGH-i617 Samsung Korea SmartphoneCU720 LG Electronics Handset I8510M Samsung Korea SmartphoneK850i Sony Ericsson Mobile Communications AB Handset Tero 750na2 Palm Smartphone6555 Nokia Corporation Handset Panther Palm SmartphoneKP330, TU330 LG Electronics Handset POLA100 HTC Corp SmartphoneHUAWEI U5705 Huawei Technologies Co Ltd Handset KAIS130 HTC Corp SmartphoneN75 Nokia Corporation Handset iPAQ 900 Series Hewlett Packard Company SmartphoneW760i Sony Ericsson Mobile Communications AB Handset SGH-i607 Samsung Korea SmartphoneiPhone 3G, A1241 Apple iPhone KAIS120 HTC Corp SmartphoneiPhone 3G S, A1303 Apple iPhone KAIS100 HTC Corp SmartphoneiPhone-A1203 Apple iPhone Model HSTNH-I14C-N (iPAQ 610, 610c, 612, 612c, 614 and 614c Insight Series)Hewlett Packard Company SmartphoneiPhone 3G S (A1303) Apple iPhone GW550 LG Electronics Smartphone

SEDN100 HTC Corp SmartphoneE72-2 Nokia Corporation SmartphoneN97-5 Nokia Corporation Smartphone


Before we continue.............some fundamentals about 3G data connections• To better understand the following discussion, the next couple of

slides explains the different connections established when transferring data in a 3G network

• Use case is web browsing from handset

• Some terminology– PDP context is between UE and GGSN– Radio Access Bearer (RAB) is between UE and SGSN– Radio Bearer is between UE and RNC


3G web browsing session

1. User clicks on link. Browser starts. Direct Tunnel PDP context and RAB is established, and a radio bearer is allocated in cell_DCH to transfer data

2. Page is transferred and user starts to read. After a short period of inactivity, the radio bearer is released and the RRC state changes first to cell_FACH and then to cell_PCH

3. User clicks on next link. New radio bearer is established in the cell_DCH state4. After long period of inactivity, network releases the RAB, and the PDP context is transformed to two-tunnel5. User clicks on another link, new RAB is established, PDP context changes to Direct Tunnel, RRC state changes to cell_DCH and

radio bearer is allocated6. User closes browser. RAB and PDP context is released

Cell_DCHCell_FACHCell_PCH

Attach

PDP context

RAB

Radio Bearer

1 2 3 4 5 6UE is always

attached


How to measure smartphone penetration?

• Several methods can be used to measure the smartphone penetration in the network– Keep track of which UE that have been sold (so also UEs that are never used are

included in the statistics)– Use RNC Traffica/RNC log files to learn which UEs that access the 3G RAN– Use SGSN Traffica to learn which UEs access the packet core network– Use Billing Records to see which UEs have transferred data– Etc.

• The result depends on which measurement method is used!• Also the duration of the measurement period plays a role• For the next slides, the following method has been used

– Data taken on April 28, 20:00 - 21:00 from SGSN Traffica– Only signalling coming from 3G RAN is included– All subscribers which have done mobility management, session management or

RANAP signalling are included– A subscriber that accessed the SGSN once has same weight as a subscriber which

access the SGSN a hundred times– In the few cases where a subscriber changed the UE, each UE is included


Smartphone penetration in SGSN Bavaria

• Table shows the number of unique subscribers with a given UE category

• In SGSN Bavaria, 27% of the subscribers are using some kind of smartphone

• Smartphone penetration not the same in all RNCs

UE category/RNC RNC01BA4 RNC02BA4 RNC01SB4 Total ShareiPhone 3798 428 155 4381 11%Blackberry 2300 181 71 2552 7%Other smartphone 2612 461 444 3517 9%Plain handset 312 109 103 524 1%Modem 10472 9876 6251 26599 69%Uncategorized 613 192 131 936 2%Total 20107 11247 7155

Share of subscribers pr UE category

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

RNC01BA4 RNC02BA4 RNC01SB4

Uncategorized

Modem

Plain handset

Other smartphone

Blackberry

iPhone

April 28, 20:00 - 21:00 from SGSN Bavaria


Smartphone penetration in other networks

• Table based on SGSN Traffica data:– 1 hour SGSN Traffica data. April 28, 20:00 - 21:00– Capital city (for Bogota: RNC01BA4 & RNC01SB4)– Networks 1, 2 and 3 are other networks in Latin America

• Share of smartphone users in Telefonica Colombia still relatively low => Expect more in the future??

UE category Network 1 Network 2 Network 3 BogotaModem 16% 33% 34% 61%iPhone 37% 39% 14% 15%Blackberry 15% 4% 18% 9%Other smartphone 21% 8% 21% 11%Plain handset 7% 9% 9% 2%Uncategorized 4% 6% 4% 3%

Unique subscribers accessing 3G Packet Core during 1 hour


SGSN signalling load• Table shows the successful

number of 3G signalling procedures coming from each RNC

• The RAB creation procedure and the PDP context modification procedures are the most frequently occuring signalling procedures seen from SGSN's perspective

• Those two procedures are related in the following way– With a PDP context already

active, RAB establishment causes the PDP context to be modified from two-tunnel to Direct Tunnel

– RAB release causes the PDP context to be modified from Direct Tunnel to two-tunnel

• Therefore the number of context modifications has a strong correlation with the number of RAB creations

• Following slides explore the RAB creation procedure in more details

Category RNC01BA4 RNC02BA4 RNC01SB4Attach 10927 7195 4593Context activation 10282 6524 4377Context modification 55937 15024 10625RAB Creation 54781 14266 10226RAU 8130 1709 5530InterRAT RAU 7018 10392 2342

Successful 3G procedures pr RNC pr hour

Successful 3G signalling procedures in the SGSNs

0

20000

40000

60000

80000

100000

120000

140000

160000


Even

ts p

r hou

r InterRAT RAU

RAU

RAB Creation

Context modification

Context activation

Attach


RAB creations as seen from SGSN

• Charts show the amount of successful RAB creation procedures

• 85% of the RAB creations in RNC01BA4 are caused by some kind of smartphone

Successful RAB creations pr UE category

0

10000

20000

30000

40000

50000

60000


Even

ts p

r hou

r Uncategorized

Modem

Plain handset

Other smartphone

Blackberry

iPhone

Successful RAB creations pr UE category

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


UncategorizedModem

Plain handset

Other smartphoneBlackberry

iPhone

RAB creations pr hour pr subscriber

012

345

6789

iPhone

Blackb

erry

Other s

martph

one

Plain h

andse

t

Modem

Uncateg

orize

dEv

ents

pr h

our p

r sub

scrib

er

RNC01BA4RNC02BA4RNC01SB4

April 28, 20:00 - 21:00 from SGSN Bavaria


Use of internal RNC logfiles

• Previous slides showed how the signalling looks from the SGSN perspective. This information was taken out of SGSN Traffica

• The next slides tackles the smartphone issue from RNC perspective

• Internal RNC logfiles from the ICSUs (Integrated Control and Signalling Units) have been taken and postprocessed

• Taken from RNC01BA4 on April 27, 15:27 - 16:12• Only RABs which are started and stopped within the monitoring

period are included in the analysis– UEs with long RABs will tend to be left out


Payload and signalling pr UE category

• 96% of the payload (DL + UL) generated by modems• 60% of the RABs generated by some kind of smartphone• Modems generating 78% of the Radio Bearers• 4 times more Radio Bearers than RABs

Traffic distribution between UE categories

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Payload RABs Radio Bearers

Uncategorized

Modem

Plain handset

Other smartphone

Blackberry

iPhone

Number of RABs and Radio Bearers

0

5000

10000

15000

20000

25000

30000

35000

40000

RABs Radio Bearers

Uncategorized

ModemPlain handset

Other smartphone

Blackberry

iPhone

RNC01BA4 on April 27, 15:27 - 16:12


Calculating distribution of payload pr Radio Bearer

• One possible way to reduce the number of Radio Bearer allocations is to increase the threshold for when the UE moves from cell_PCH to cell_DCH. To predict how efficient this method will be, it is necessary to estimate how many Radio Bearers that contain payload below a certain threshold

• Although the ICSU logs themselves contain information about the transferred payload for every allocated Radio Bearer, this information is not available in the current postprocessing tools

• Instead, for each RAB, it is noted down how many Radio Bearers that have been allocated, and what was the combined payload of those Radio Bearers– In case there was only 1 Radio Bearer allocated in the RAB, it is straightforward to

calculate how many Radio Bearers that contained data below a given threshold– In case there were more than 1 Radio Bearer allocated in the RAB, it is assumed that

each Radio Bearer transferred the same amount of data, and it can then straightforwardly be calculated how many Radio Bearers that were below the threshold


Distribution of payload pr Radio Bearer

• Distribution estimated as explained in previous slide• For example, 27% of the Radio Bearers were estimated to have less than 1 KByte DL

payload• Current network settings means that data bursts less than 128 bytes are transferred in the

cell_FACH state– Increasing the threshold means more data bursts transferred in cell_FACH and less that need the

dedicated radio bearer of cell_DCH

Estimated distribution of DL payload pr Radio Bearer

0%2%

4%6%

8%10%

12%14%

16%

0 - 1

28 B

128

- 256

B

256

- 512

B

512

- 10

24 B

1 - 2

KB

2 -

4 KB

4 -

8 KB

8 -

16 K

B

16 -

32

KB

32 -

64

KB

64 -

128

KB

128

- 256

KB

256

- 512

KB

512

- 102

4 K

B

1 - 2

MB

2 -

4 M

B

4 -

8 M

B

8 -

16 M

B

16 -

32 M

B

32 -

64 M

B

64 -

128

MB

128

- 256

MB

Bin

Shar

e of

RBs

RNC01BA4 on April 27, 15:27 - 16:12


Fast Dormancy and Quick Release

• As explained previously, the idea of cell_PCH is that the network keeps the "virtual" RAB during inactivity while the "real" resources are released

• However, not all UEs respect this concept– iPhone v. 3.0 implemented the "Fast Dormancy", so after short period of

inactivity, the UE requests the SGSN to release the RAB - even if the UE has been transferred to cell_PCH

– Blackberry handsets have the same behaviour– Latest Nokia handsets have "Quick Release". After 6 seconds of inactivity, the

handset checks if it is in cell_PCH. If yes, it does nothing. If no, it asks for RAB release. Current network timers are cell_DCH => cell_FACH = 2 - 5 seconds, depending on radio bearer cell_FACH => cell_PCH = 2 seconds


Fast Dormancy and Quick Release

• Almost all the Blackberry RABs are released at the UE's request, while some of the iPhone RABs and some of the Nokia RABs are also released at the UEs request– iPhone RAB releases might be reduced by asking Apple to disable Fast Dormancy– Nokia RAB releases might be reduced by tuning the RRC state timers

• No big impact at the moment, so no urgent action required

RAB release reasons, top-10 UE models

0%10%20%30%40%50%60%70%80%90%

100%

ZTE MF11

0

Huawei

E1756

Huawei

E160

ZTE MF62

6

iPhone

3G, A

1241

iPhone

3G S

, A13

03

RIM 90

00

RIM 97

00

Nokia

E63-2

Nokia

E71-2

Cell-FACH_rel_ue_gen_c

Cell-DCH_rel_ue_gen_c

Others

Cell-FACH_configuration_unsupport_c

Cell-DCH_inter_system_hard_ho_c

Cell-PCH_user_inactivity_c

Cell-FACH_user_inactivity_c

Cell-DCH_normal_release_c

Cell-PCH_default_c

Cell-FACH_default_c

Cell-DCH_default_c

RAB release reasons, top-10 UE models

0

200

400

600

800

1000

1200

1400

1600

ZTE MF11

0

Huawei

E1756

Huawei

E160

ZTE MF62

6

iPho

ne 3G

, A124

1

iPhone

3G S

, A13

03

RIM 90

00

RIM 97

00

Nokia

E63-2

Nokia

E71-2

RAB

rele

ases

in 4

5 m

in Cell-FACH_rel_ue_gen_c

Cell-DCH_rel_ue_gen_c

Others

Cell-FACH_configuration_unsupport_c

Cell-DCH_inter_system_hard_ho_c

Cell-PCH_user_inactivity_c

Cell-FACH_user_inactivity_c

Cell-DCH_normal_release_c

Cell-PCH_default_c

Cell-FACH_default_c

Cell-DCH_default_c

RNC01BA4 on April 27, 15:27 - 16:12


Possible optimization actions

• Reduce the number of Radio Bearer establishments by– Using cell_FACH state to transfer small amounts of data– Possibly keep the cell_DCH state longer so small gaps in the data stream

don't cause Radio Bearer release (but at the cost of less efficient resource usage)


Summary

• Most of the current subscribers are using modems• Bogota has higher smartphone than outside Bogota• Other networks have higher smartphone penetrations than

Telefonica Colombia• Smartphone penetration in the network is still so low that it doesn't

have big impact on the network elements• From RNC perspective, it is still the modems that generate most of

the signalling– Some optimization actions are possible, this will be discussed further in the

RAN assessment part

smartphone impact

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