Tomorrow’s Thinking,
resulTs Today


WHITE PAPER

STOKE Mobile Data Offload:
Retooling 3G Networks for
Today’s Mobile Internet Realities

July, 2011


Stoke Mobile Data Offload


Table of Contents

Introduction ......................................................................................................3
Stoke Mobile Data Offload Solution Overview................................................3
How It Works....................................................................................................4
Impact to Existing Network Nodes..................................................................5
Stoke Mobile Data Offload Financial Benefits.................................................5
ROI Model Results .......................................................................................... 6
Beyond Core Offload .......................................................................................7
Stoke Mobile Broadband Technologies ...........................................................8



Stoke Mobile Data Offload

Introduction

One of the biggest business challenges for Mobile Network Operators (MNOs) today is efficiently managing
the unrelenting growth of mobile data traffic for a subscriber base with an increasingly “Always On,”
“Always Connected” expectation.

What is perhaps even more disturbing to MNO executives is that their incumbent suppliers have yet to
provide a clear direction to overcome this dilemma. They are failing to deliver any real breakthroughs while
attempting to solve completely new problems using outdated or legacy-thinking. There is a clear and
urgent need for new ideas in order to solve these new problems.

Stoke introduced to the market a unique method of providing data offload using a pioneering, yet 3GPP
standards compliant approach, to help Mobile Network Operators (MNOs) address the growth of mobile
data. In contrast to incumbent vendors, Stoke examined all the issues including deployment, cost, service
level requirements and user experience, and in consultation with several leading mobile operators has
produced Stoke Mobile Data Offload (MDO) which enables:

. Mobile Core CapEx and OpEx cost reduction
. RAN savings through intelligent optimization
. RAN to Core Backhaul Savings
. Enablement of selective tiered services
. Improved User Experience
MDO brings current mobile infrastructures into the Internet era, and as a standalone solution can save
mobile operators tens of millions of per year by delaying capacity expansion capital expense and the
operational costs to maintain an over-built network.

Enhancements resulting from operator engagement over the past years is fostering the creation of a
nascent ecosystem of mobile network application providers who are finding new ways to drive efficiencies
in and costs out of network operations from the MDO insertion point. This new “service exchange”
involves content acceleration, optimization and control solutions that deliver even greater savings, service
management, and enhanced user experience.

MDO and the emerging service exchange mark clear examples how Stoke helps operators think outside
the legacy-thinking box to find new ways to improve mobile data service delivery, and achieve their
business objectives.

Stoke Mobile Data Offload Solution Overview:
“Breaking Out” of the Core

Stoke Mobile Data Offload (MDO) enables operators to manage mobile broadband traffic in ground-
breaking ways, without the constraints imposed by the mobile core network legacy architecture. Deployed
at the edge of the RAN on the Iu-Ps interface, MDO seamlessly intercepts mobile data sessions and routes
the traffic direct to the internet. This enables the operator to avoid costly and unnecessary core network
infrastructure upgrades, while providing a conduit to enhance service delivery and gain better subscriber
insight.


Figure 1: stoke 3gPP mobile data offload


Stoke Mobile Data Offload

not an all or nothing proposition, mdo gateways can be deployed where necessary
throughout the network to alleviate highly congested regions of the network, without
requiring any reconfiguration or upgrades to existing 3gPP network elements.

MDO supports a comprehensive range of configurable filters that enable operators to select the most
appropriate users, devices, or traffic streams for offload, leaving low impact traffic to flow through the
existing core network as required. The offload filters support selection of subscriber data sessions by the
widest range of attributes, including:

static offload Criteria

.
IMEI TAC code to offload a class of devices, for example all iPhones or 3G USB data dongles
.
APN used to differentiate service classes
.
GPRS QoS negotiated, to offload sessions that have been marked with a QoS indicative of a high
network bandwidth (e.g. multimedia sessions)
.
Location / Service Area Code to offload traffic from known traffic hotspots
.
Time of day to provide offload at peak times only
active offload Criteria

.
IMSI or IMSI ranges to pick out individual “special” subscribers
.
RADIUS / Diameter calls to AAA server to discover current offload requirement for this subscriber
dynamic offload Criteria (applied post PdP Context activation)

.
Application type
.
Source IP
.
Destination URL
How it Works

When a subscriber session matches an offload rule, the PDP context control plane signaling is modified
by MDO so that the data plane RNC GTP tunnel is terminated at the MDO gateway, not the SGSN. The
MDO gateway then directs the data to the required IP end point, such as MNO’s Service LAN, direct
Internet peering point, or distributed services including CDN. Once a PDP context has been established,
the MDO solution continues to manage and maintain the session in accordance with 3GPP standards and
recommendations. For example, all mobility and roaming scenarios are correctly handled to ensure that
data services are provided correctly.


Figure 2: stoke mdo: non-intrusive data offload


Stoke Mobile Data Offload

MDO is designed to meet today’s network and integration requirements, and has completed IOT with ALU
RAN components and Ericsson core components. Specifically, it supports the following capabilities:

. Direct tunnel architecture
. Lawful Intercept mediation system integration
. Billing system integration via Diameter and RADIUS
. NAT for correct UE IP pool management
Impact to Existing Network Nodes

Stoke is conscious that there is a clear boundary between the RAN and core networks and that they are
discrete, complete entities. Each has its own management, planning, and engineering organizations, and
often times each has its own incumbent equipment supplier. MDO sits squarely on the demarcation line
between these two domains and can be deployed without hardware, software or configuration changes
to the existing RNCs, SGSNs, or GGSNs. This results in a dramatically different deployment cost profile
between the Stoke solution and the options provided by incumbent suppliers. Moreover, MDO is network
agnostic and can be deployed in any RAN / core network combination.

The Stoke offload solution does require interaction with the transport network. While MDO decides what to
breakout and where it will be sent, it is a transport node’s responsibility to force Iu-PS traffic to the MDO
gateway on its way to the SGSN. This is accomplished in the transport router sending all the SCTP traffic
to the MDO gateway.

Stoke Mobile Data Offload Financial Benefits

The location of the MDO between the RNC and SGSN means that the core network elements, SGSN and
GGSN, are completely bypassed for some - perhaps most - data traffic, dramatically reducing the capacity
requirements for these core network elements. To illustrate the magnitude of the potential savings, Stoke’s
Offload ROI model was tuned to model the effects of projected increase in data usage on the capacity
demands for the GGSNs and SGSNs. The model then compares the capital and operational expense
for the present mode of operations (adding SGSN/GGSN capacity as needed) against a future mode
of operations (FMO) of deploying MDO. In addition, since operators have the option to upgrade their
networks to higher capacity core network elements, and indeed to a Direct Tunnel architecture, Stoke’s
ROI tool was tuned to model these scenarios as well.

Key business case example assumptions:

Beginning subscriber base 15,000,000
Percent of subs have data plan today 40%
Data plan penetration in year 5 85%
Data traffic destined to Internet APN and the Internet is 85%
Average data use volume per sub per month to start 500Mb
Average data use growth projected over the 5 year period 45

Table 1: roi model example operator / subscriber Characteristics

The key assumptions regarding the mobile operator model are listed in Table 1 above. They include the
details of the current subscriber base and data plan growth factors. It also includes charateristics of the
data usage per user today and forecasts for the end of the period. Actual network characteristics may
vary and based on conversations with operators around the world, the profile used here tends to be on the
conservative side.


Stoke Mobile Data Offload


Figure 3: dramatically improved scalability with mdo

ROI Model Results

This is a comparison of the cost to provision the mobile data core network elements to handle the
forecasted traffic loads using current generation SGSNs and GGSNs. MDO offers tremendous savings over
today’s present mode of operations. Figure 3 above illustrates model results by comparing the number
of network elements that will need to be added to the network to manage the forecasted data traffic. The
chart is not to scale, but the element counts tell the tale.

The network that includes stoke mdo requires only 76 additional network elements
by year 5, while networks continuing to deploy current generation ggsns and
sgsns will require 310! not only does this mean a significant CaPeX reduction, but
an astounding reduction in network complexity. This simple comparison alone shows
just how unsuited the current mobile network is for today’s data traffic growth.

The Table 2 below presents the financial view of the two methodologies. We see that over the 5 year period,

MDO reduces mobile data core CAPEX by 89% and OPEX 88%. The net addition cumulative cash
flow resulting from MDO deployment is $201 million. MDO clearly enables MNOs to scale the data
capacity of the mobile network in a much more controlled fashion, and ensure profitable growth.


Table 2: stoke roi model summary


Stoke Mobile Data Offload

Beyond Core Offload: Innovation at the Edge

While the business benefits of offloading core network elements are substantial and irrefutable, and
subscriber QoE can be expected to improve due to reduced latency, MDO has given rise to additional
capabilities not previously possible. Given the location of the MDO gateway deployment and its access
to control plane messaging in that location, MDO is also fostering a new ecosystem of network services
technology partners . an “service exchange” (see Figure 4 below). The MDO gateway affords typically
core-bound network services including caching, optimization, and analytics a new and unique look at data
sessions and traffic, and an opportunity to deliver new levels of performance and control.

Service Manager
Figure 4: stoke mdo and the service exchange

In lab testing, for example, the benefit of locally accessed content cache vs. content accessed at its
source or even from non-local caching servers is proven (see Table 3 below). Latency is the most critical
component in a subscriber’s Mobile Internet experience: Geographical location introduces latency; network
nodes introduce latency; and DNS resolution introduces latency. By bypassing the core network and
bringing the content closer to the subscriber, the Service Exchange greatly reduces the end-to-end latency
and dramatically improves end user experience.


Table 3: impact on website download times of stoke mdo and mobile Cdn

*non offloaded traffic (50ms 3G CN latency) using public internet
**offloaded traffic (3G CN bypassed) using public internet
***offloaded traffic using local CDN edge server (co-located with SSX)


Stoke Mobile Data Offload

MDO can also supply subscriber location information to Service Exchange systems for unique
service innovation, such as optimization based on regional location. This increases the degree of control
operators have over traffic reduction tools to better balance subscriber satisfaction and network resource
management.

The Service Exchange involving several technology partners has been trialed with a tier-1 operator in
Europe. The trial included the following capabilities:

. Selective session breakout
. Optimization solutions
. CDN and caching solutions
. DNS caching
. Policy Enforcement
. Subscriber service usage analytics
Stoke Mobile Broadband Technologies

Hyper-growth of mobile data and mobile Internet use is the new “normal.” Operators must consider all
possible remedies to legacy 3G architectures to enable more efficient handling of Internet traffic, and must
look to the industry’s innovators for answers. Stoke is one such innovator.

With its combined set of session management capabilities, multi-access support, performance scalability,
and pay as you grow economies, Stoke’s transformation platform and solutions are designed for the cost-
effective and high-performance delivery of service over mobile network technologies without disruptive
network modifications.

These core capabilities have been applied to allow operators to offload Internet traffic within their 3G
network, ensuring that they retain control of the session, while reducing the cost of service delivery.

stoke mobile data offload is an application that uniquely positions standards-
defined functionality to achieve compelling traffic handling efficiencies for today’s 3g
networks and drive service delivery costs out.

Moreover, an ecosystem of network services technology partners is emerging around Stoke’s MDO
gateway, forming a new “Service Exchange” at the edge of the RAN. The MDO gateway brings typically
core-bound network services such as caching, optimization, policy enforcement, or analytics closer to the
edge to dramatically improve end user experience and enhance operator control.

Stoke solutions are deployed on its award winning SSX-3000 mobile
broadband gateway platform; the same platform that has been
deployed by NTT Docomo for their 3G Femtocell and LTE services. The
SSX-3000 has been delivering active customer traffic since November
2009. And while performing a different set of functions than MDO for
Docomo, the SSX-3000 completed thorough and rigorous testing by
the Docomo service development engineers to win selection and prove
its value over competing systems.

Find out more at www.stoke.com.

Figure 5: stoke session exchange


www.stoke.com

Stoke, Stoke Session Exchange and the Stoke logo are trademarks of Stoke, Inc. Copyright ⓒ 2011 Stoke, Inc. All rights reserved. Lit# 130-0010-004