Overview

Mobile data consumption is increasing exponentially

because of sophisticated smartphones that drive

consumer demand for downloading, streaming,

browsing, and sharing content. While new types

of applications and feature-rich functionality

are proving extremely popular, they also pose

a significant challenge for operators given the

impact they have on network performance and

the customer experience. Many of these apps

are “chatty” in nature, signalling the mobile

network for hundreds and even thousands

of updates every hour.

Managing this mobile environment is made

more challenging because the ecosystem is in conflict.

Device manufacturers want improved battery life,

the app development community want the

“killer app”, while operators want increased

data usage with a good experience at a

lower cost to the network. This has to be

achieved using an infrastructure where

radio resources are limited and where the

volatile nature of today’s traffic is producing

wide, non-correlated variations in traffic volume, airtime

usage and radio signalling.

This excess signalling has a significant impact on network

resources, leading to poor customer experience and in

some case network outages. In Japan, NTT Docomo

recently suffered an outage that left 2.5 million customers

without a service for four and half hours. The operator was

already in the process of upgrading its network to cope with

increased signalling traffic from smartphones, a process

that has been ramped up significantly at considerable cost.

Continuous investment to increase capacity of the RAN

(Radio Access Network) is not economically viable.

Operators must seek alternative solutions to help them

stay ahead of the data curve. This must be achieved in

Managing the Signalling Storm

| W

HIT

E PA

PER

a manner that addresses the most immediate need to

control signalling volume growth and extend smartphone

battery life without impacting on the customer’s Quality of

Experience (QoE ).

The Operator Dilemma

Smartphone success

Smart devices are growing at

an explosive rate, driven by the

demand for accessing feature-

rich content on the move.

According to Informa, smart

device shipments are expected

to reach over 500 million units in

2016. In tandem with this, the

growth of mobile applications

continues at pace with forecasts

predicting that the total number

of downloads will reach 185 billion

by 2014. This increase is driving

the adoption of Over The Top

(OTT) services, including a new

wave of Instant Messaging (IM) apps from third parties that

threaten operators with lost revenue and disengagement

with customers.

Existing operator business models are already being eroded

as the mobile Internet and open device platforms combine

to create new ecosystems for third-party application

developers. The mobile development community has

momentum and will continue to deliver applications across

multiple platforms and channels, offering more creative and

innovative messaging experiences.

Smartphone traffic patterns – bursty behaviour

While operator’s initial concerns were around the exponential

growth in data volume due to the widespread and growing

popularity of smartphones, issues relating to signalling

capacity have presented the operator with an even greater

challenge. The most popular smartphone applications –

including push email, social networking, online gaming and

news reports – combined with in-application advertising,

are “chatty” by nature and require regular connections to

the network for updates. These chatty apps send small

amounts of data (packet bursts) at very regular intervals

over separate short-lived connections. The requirement

characteristics of such apps cause a bi-directional ping-

pong of messages between the smartphone device and

application servers in the Content Delivery Network (CDN).

This frequent communication is known as transactional

behaviour and leads to a disproportionate increase in radio

signalling load relative to data transmitted.

As networks become congested with mobile data traffic

and the underlying signalling overhead associated with

devices constantly connecting and disconnecting from

the network, the customer experience can degrade to

unacceptable levels. Slow network response times, poor

battery performance, low data rates and dropped calls are

just some of the undesirable characteristics of a network

that is strained to its limits. Even with such overheads

placed on operators, they are still expected to deliver an

0

100

200

300

400

500

20112010 2013 2016201520142012

Symbian Android Apple iOSx Blackberry OS (QnX) Microsoft Linux Total† web OS

INFORMA TELECOMS & MEDIA FORECAST ON SMART DEVICES BY OS : 2010-2016

SALE

S VO

LUM

E (M

ILLI

ON

)

YEAR:

| W

HIT

E PA

PER

optimal quality of experience to their customers thereby

exacerbating the problem.

Application developers have little or no visibility into the

resource-constrained mobile execution environment

resulting in smartphone applications that are typically not

mobile friendly. However, the recent publication of the

‘Smarter Apps for Smarter Phones’ by the GSMA presents

a set of guidelines to encourage application developers

to write “better behaved” software. By following these

recommendations, developers will be better equipped

to create fit-for-purpose apps; mobile operators will

see a reduced strain on network overload, and users

will experience more responsive and reliable apps and

improved battery life.

Operators need to take their place profitably within the

value chain to mitigate risks and deliver the right value

and blend to their customers. They need to innovate their

business model to work more closely with all members of

the ecosystem and encourage adoption of frameworks

such as those outlined above. As a result, mobile operators

are forming a symbiotic relationship with application

developers and device manufacturers to ensure valuable

network resources and the customer experience are not

undermined.

Taking proactive measures – Intelligent network monitoring

It is essential operators have early visibility into the growth

and impact of chatty applications in order to ascertain the

potential impact on the radio network and to identify the

most appropriate strategy to alleviate the problem.

When reviewing this issue, the mobile operator cannot

test a single element in isolation. Instead, they must focus

on all contributing factors. The same application running

on different devices and OS versions may have a vastly

different effect on the network.

By using intelligent network monitoring systems, the

operator can glean insights into which applications,

devices, OS versions and combinations of each are

contributing most to increased signalling load on their RAN.

Using a signalling load or aggressiveness score against

each of these dimensions enables operators to address the

issue early.

Armed with this actionable intelligence through real time

reporting, the operator can set about implementing a

strategy to ensure an optimum performance balance for

handsets, their batteries, applications, networks, and most

importantly the end user.

Operators need to take their place profitably within the value chain to mitigate risks and deliver the right value and blend to their customers.

| W

HIT

E PA

PER

Measuring the impact of application signalling

Actionable insights into network traffic offer a unique and

pre-emptive approach to the problem because they identify

potential issues before the full force of the signalling affects

the customer experience. Armed with the right intelligence,

operators can avoid costly network upgrades that are an

expedient response to excess signalling that undermines

the customer experience.

To measure signalling impact, operators need to capture

detailed profiles of mobile applications in addition to

undertaking proactive modelling. Being able to measure

the bursty behaviour of apps, coupled with the ability to

identify apps before they go viral, are valuable weapons for

operators as they look to control the impact of application

signalling.

a. Profiling mobile applications

In order to accurately assess how efficiently an application

(or device/user/operating system) is utilising radio signalling

resources to transmit and receive data, the application

traffic is characterised in terms of packet bursts. By

using bursts to analyse the traffic, it is possible to extract

information about activity and inactivity periods during a

data session.

Consider a typical smartphone user with multiple

applications running in parallel (e.g. Gmail, WhatsApp,

Facebook, Google maps). Each application exhibits a

different traffic pattern and will send packets into the

network over separate data streams. Small amounts of

data are sent at irregular intervals causing the user’s device

to wake up, send some data and go back to sleep.

The latency between application bursts causes the device

to transmit between Idle and Connected mode

each time a connection is required to send

data. This causes a massive surge in radio

signalling due to the high number of RRC

state promotions and demotions involved

(~26 RRC messages round trip per connection

setup). Based on these insights, sessions with

anomalous traffic burst patterns are obtained

and the cumulated impact of applications and

devices on radio signalling capacity is exposed.

b. Proactive modelling

By extracting properties of traffic that exhibit

inefficient bursty behaviour, it is possible

to proactively identify new threats to RAN

resources if certain combinations

of applications and devices with

inefficient behaviour increase in

popularity.

For example, an application

might be very bursty but not very

popular, thereby having little impact

on signalling capacity. However,

if that application goes viral and its

popularity increases exponentially in

a short period of time, the cumulative

impact of bursty behaviour across a high

number of devices will significantly increase

the signalling involved and pose a real threat

to the normal functioning of the RAN.

| W

HIT

E PA

PER

SMARTPHONE SALES FORECASTS 2012 - 2016 (MILLIONS OF UNITS)

REGION 2012 2014 2016

NORTH AMERICA 105.51 118.92 127.4

LATIN AMERICA 34 59.43 94.15

ASIA PACIFIC 178.63 249.04 344.24

EUROPE 162.79 192.94 221.24

MEA 39.06 59.66 82.98

TOTAL 520 680 870.02

Conclusion

Signalling volume growth poses a significant

challenge for mobile operators that will only get worse.

Mobile data services are a hotbed of innovation and a

commercial opportunity that app developers and third-

party providers will continue to explore, putting more

strain on the network, creating greater challenges

for operators as they try to ensure the best possible

customer experience for their customers.

Investing in network capacity, building ecosystem

partnerships and attempting to optimise assets and

devices may offer a short-term fix, but long-term,

operators need to become more proactive and assume

the driving seat.

With intelligent network monitoring and by measuring the

precise impact of signalling by device, application and

service, the operator is in a much better position to deal

with the challenges and manage the storm.

About The Now Factory

The Now Factory provides operators with rich insights

around the use of mobile data services, helping optimise

the customer experience and drive greater profitability.

By providing tools and solutions to quickly detect and

measure the effects of emerging applications on the

network, The Now Factory enables operators to be proactive

and plan against the impact of excessive signalling, rather

than respond with expedient measures that are short-term

and expensive.

The Now Factory empowers operators to mitigate the risk

of network degradation and poor customer experience, all

the time driving increased cost-efficiencies.

Copyright © The Now Factory 2012. All Rights Reserved. All data contained in this white paper is for information purposes only and is subject to change without notice.

HEADQUARTERS

The Now FactoryCedarhurst BuildingArkle RoadSandyford Business ParkDublin 18Ireland

Tel: +353 1 297 3388Fax: +353 1 297 3381

NORTH AMERICA

The Now Factory800 West El Camino Real, Suite 420Mountain ViewCA 94040USA

Tel: +1 650 294 4091

SINGAPORE

The Now FactoryLevel 42Suntec Tower Three8 Temasek BoulevardSingapore 038988

Tel: +65 6829 2392

SPAIN

The Now FactoryIslas Aleutianas 4 BisPuerta Derecha, Puerta 2Madrid 28035Spain

Tel: +34 607 805 765

Email:info@thenowfactory.com Website: www.thenowfactory.com

| W

HIT

E PA

PER