www.tekelec.com
WHITE PAPER
A Revolution in EvolutionPolicy Control and Mobile Broadbands Long-term Leap
A REvoluTIon In EvoluTIon
This document is for informational purposes only, and Tekelec reserves the right to change any aspect of the products, features or functionality described in this document without notice. Please contact Tekelec for additional information and updates. Solutions and examples are provided for illustration only. Actual implementation of these solutions may vary based on individual needs and circumstances.
2010 Tekelec. All rights reserved. The EAGlE and Tekelec logos are registered trademarks of Tekelec. All other trademarks are the property of their respective owners. TKlC-WP-028-nA-06-2010
Tekelec Global Headquarters +1.919.460.5500 [email protected]
EMEA +44.1784.437000 APAC +65.6796.2288 CALA +1.919.460.5500
Tekelec has more than 30 offices worldwide serving customers in more than 100 countries. Addresses, phone and fax numbers are listed on the Tekelec website at www.tekelec.com/offices.
A REvoluTIon In EvoluTIon
Table of ContentsExecutive Summary .....................................................................................4
Mobile Broadband and long-term Evolution ...............................................4
Policy and Charging Rules Function: Rules of order .....................................6
The Primacy of Policy ..................................................................................8
About Tekelec .............................................................................................9
4A REvoluTIon In EvoluTIon
Executive SummaryArmed with spectral efficiency, support for higher data rates and all-IP infrastructure, the
standards for the mobile broadband architecture known as long Term Evolution (lTE) are
arriving on the scene at just the right time. Coupled with policy approaches that allow
for intelligent management of network resources, lTE architectures offer tremendous
promise for solving a big problem confronting the industry: the current imbalance
between bandwidth demand and revenue generation. As lTE networks begin to be
deployed, the staging ground for a bold new era of mobile broadband is taking shape.
Mobile Broadband and Long-term EvolutionMobile broadband has clearly become the new growth engine in the mobile industry.
Carriers around the world are reporting large increases in revenue from data services,
driven in large part by mobile internet access, either through smartphones or via
personal computers. numerous mobile operators, especially in Europe, have begun
to offer subsidized netbooks small, low-cost laptop computers geared for internet
access bundled with a contract for mobile internet access. In many countries including
Austria, Germany, Ireland, the netherlands, Sweden, Finland and Portugal, contracts
for a 3GB+ mobile broadband service are lower than fixed line DSl services offered by
incumbents.1 Perhaps the best example of the impact of data growth on operators
revenue comes from vodafone Group, which reported organic revenue growth of 25%
for its data services for Q408 whereas the organic growth of voice and messaging
revenue remained flat. Clearly, mobile broadband will power the next phase of growth
for the mobile industry.
However, this growth does not come for free. For voice and messaging traffic,
bandwidth cost was well understood and relatively constant. The same is not true for
data. Different applications demand widely varying amounts of bandwidth. A text email
from a Blackberry may only consume 1 or 2 kilobytes (KB) of data with no stringent
concerns about latency. on the other hand, standard web pages often demand 500KB
of data or more, while video services can easily consume megabytes if not gigabytes
with latency a key quality concern. Despite the early stage of mobile broadband,
several operators have already crossed the threshold where their networks have more
data traffic than voice traffic.2 The result of this growing customer base and increased
bandwidth per user is that bandwidth capacity needs are growing much faster than
revenue. For example, Motorola projects 3G network operators in developed markets will
see 14 times (or higher) growth in bandwidth demand in 2009 while revenue grows only
up to 30%.
1. Analysys Mason, Sept. 2008
2. T-Mobile uK, 2008, Ericsson, 2008
5A REvoluTIon In EvoluTIon
Against this backdrop, products based on a set of standards called long Term Evolution,
or lTE, have recently arrived for an industry looking for help.
lTE was initiated in 2004 by the Third Generation Partnership Project (3GPP*) to define
a next-generation high speed radio access method. The main high level features of lTE-
based products are:
Support for higher speed data rates with theoretical downlink rates of up to 300 Mbps and uplink rates of up to 75 Mbps per 20Mhz of paired spectrum
Greater spectral efficiency to support larger numbers of customers for a given spectrum band at a lower cost per bit delivered
Flexible spectrum and deployment usage to allow lTE products to work in new and existing spectrum bands in a wide range of cell sizes
Reduced round trip and MAC state transition latency for faster response times
An all-IP network architecture
The first four feature areas deal primarily with improvements in the radio access network
technology, incorporating advances such as orthogonal frequency-division multiplexing
(oFDM), 64QAM modulation, more sophisticated error correction and multiple input/
multiple output (MIMo) and beam forming antennas. By achieving a 5x to 10x increase
in supported data rates and an estimated 70% lower cost3, suffice it to say the radio
engineers have achieved a remarkable set of advances.
The efforts to create an all-IP network were developed in 3GPP under the name Systems
Architecture Evolution (SAE), with the all-IP core network referred to as the Evolved
Packet Core (EPC). The goal was to enable use of more flexible and cost-effective IP
technology throughout the network, while at the same time providing a common core
network to enable application usage across 3GPP and non-3GPP (CDMA, DSl, cable,
etc.) access networks. This would facilitate multi-screen services, allow operators to
build and maintain one core network as well as more effectively utilize IP-based access
methods such as femtocells and dual mode devices to offload the macro radio network.
According to the Global Mobile Suppliers Association, 26 operators have committed to
deploy commercial lTE networks, 10 of which are planned for 2010 including launches
from verizon Wireless, TeliaSonera and nTT DoCoMo. Dittberner Associates projects the
number of lTE subscribers will grow from 3M in 2011 to over 1 billion by 2018.
3. nortel networks, 2007
6A REvoluTIon In EvoluTIon
Policy and Charging Rules Function: Rules of Order one of the key components of a 3GPP core network is a Policy and Charging Rules
Function (PCRF), which performs dynamic bearer and bandwidth control, charging rule
provisioning and in certain cases, lawful intercept control. The PCRF provides a single
place where the operator can implement business rules to dynamically control usage of
the network and how much to charge for particular services. For example, one common
use of the PCRF is to temporarily reduce bandwidth during peak hours for users that go
over their monthly usage quota in order to reduce the overall peak demand that drives
network capital expenditures. At the same time, the application specific control made
possible by the PCRF could also provide full bandwidth at a different charge for those
premium services that are paid for outside of the basic data service.
The PCRF was introduced in Release 5 of the 3GPP standards and has evolved as part of
Releases 6 and 7. The initiative within 3GPP that has been managing the PCRF related
issues is referred to Policy Control and Charging or PCC. In recent years, the PCRF has
become a regularly deployed element using DIAMETER-based interfaces to communicate
with applications (via the Rx interface) and the GGSn (via the Gx interface). To date, the
only access network expected is a home 3GPP-based network where the access gateway
is the operators own GGSn. With data roaming becoming much more common and
additional non-3GPP access networks expected, the fundamental change introduced
in Release 8 splits the PCRF into a home network element (H-PCRF) and visited
network element (v-PCRF) where the visited network may or may not be a 3GPP-based
mobile network.
Control PlaneData PlaneRoaming, FMC
3GPP Network,Home Network
Non-3GPP Network, Visited Network
Non-3GPP GW SGW
HSS
PCRF
PGW
ePDG
Figure 1: 3GPP Evolved Packet Core
7A REvoluTIon In EvoluTIon
The H-PCRF and v-PCRF communicate via a new DIAMETER-based interface called S9 in a
similar fashion to the way HlRs and vlRs communicate today. This function is sometimes
referred to as policy peering. There are three basic implementation options expected:
An implementation (Figure 2) where there are separate PCRFs for the home and visited networks and where all bits are routed back to and controlled by the home
network.
An alternative architecture where traffic is routed directly to the internet by the foreign network with home-based service control enabled by an H-PCRF.
A third non-roaming case where assuming the PCRF is capable of managing both 3GPP and non-3GPP access networks, there would be a single PCRF for any type of
local access network.
Non-3GPP Network,Visited Network
3GPP Network,Home Network
AF
V-PCRFS9
Rx
H-PCRFSp
SPR
Gxx Gx
BBERF PCEFGy
OSC
Gz
OFCS
Control PlaneRoaming, FMC Data Plane
Figure 2: 3GPP Release 8 PCC Architecture (Home Routed Access)
Another substantial change is that because the architecture expects non-3GPP access
networks, the access gateway will no longer always be a GGSn and as a result will have
different QoS and charging capabilities. Therefore, a generic non-3GPP access gateway
is defined as a Bearer Binding and Event Reporting Function (BBERF) controlled by
variants of Gx (such as Gxa, Gxb, Gxc, etc. referred to generically as Gxx) according to
the gateways capabilities. For example, non-3GPP gateways could include a Packet Data
Gateway (PDG), a CDMA PDSn, a cable CMTS or a telco B-RAS.
8A REvoluTIon In EvoluTIon
Release 8 PCC changes also include support for three additional features in recognition
that networks are becoming much more complex:
Support for mobile IP, in large part driven by the use of mobile IP to manage and control data services over foreign and non-3GPP access networks,
Management of mixed IPv4 and IPv6 environments,
Support for diameter routing agent (DRA) functionality, where a proxy or redirect agent acts as a central contact and routing point for DIAMETER sessions even if there are
multiple PCRFs in a network. In this way, applications, gateways and other PCRFs (e.g.
v-PCRF) dont have to know which PCRF to go to for a given session. The requests goes
to the topology aware DRA, which then routes the requests to the appropriate PCRF.
lastly, during implementations of Release 7 PCRFs for uMTS and HSPA networks,
participants have realized that several additional types of policy rules would be very useful:
Allocation and retention policies Policies that can implement prioritization of certain flows, including pre-emption capabilities and vulnerabilities
Aggregated maximum bit rate per APN Subscribed and authorized bandwidth maximums for an APn as a whole
Authorization of default bearer QoS The basic QoS parameters for the default best-effort data service flow. The importance of this function became especially evident
with the higher bandwidth of HSPA networks to create multiple bandwidth-based
service tiers. Given the very high bandwidth that can be achieved by lTE and the likely
multiple tiers of service that will be used, this function will continue to be very useful.
Time of day based rules Situations such as the activation and deactivation of rules based on time of day and time-based session revalidation. This is particularly useful as
operators have realized that session treatment should vary during peak and off peak
hours in order to maximum throughput while minimizing costly network congestion.
Credit related event reporting To allow operators to use Gx to manage QoS in response to quota related Gy events, certain Gy events such as final unit actions and
quota reallocation are reported over Gx. Again, the usefulness of this feature became
important in HSPA networks, and will become even more important with lTE.
The Primacy of Policy The EPC of Release 8 requires a PCRF for some obvious reasons and some not-so-
obvious reasons. The most obvious reason is that as services are implemented from
foreign and non-3GPP networks with widely varying QoS and cost metrics, a service
will perform and cost differently based on which network the user is located on. For
example, most femtocell and dual-mode services encourage use of the local network by
exempting any voice call minutes and data usage from the users quota. The payoff for
the operator is removing the traffic from the macro radio network. At the same time,
operators want to make sure the service works as well if not better than the same service
on the macro radio network moving on-net voice calls to voIP calls using an over the
top broadband connection will be unsuccessful if the calls lack clarity.
9A REvoluTIon In EvoluTIon
The not-so-obvious reason has been demonstrated by uMTS & HSPA networks, and will
continue to rise with the greater bandwidth of an lTE network. In pre-uMTS networks,
users could be provided as much bandwidth as the network could support because there
was so little bandwidth available to a single user. With data rates growing tremendously,
the use of multiple tiers of bandwidth and QoS is becoming much more common
either as a further point of differentiation for market segmentation, or to control
network abuse. looking at fixed-line networks that are capable of very high bandwidth
services shows what is likely to be in store for lTE networks just because the network
can deliver 30Mbps doesnt mean customers are going to get that level of service
automatically. FTTx and DoCSIS 3.0 networks are capable of delivering up to 100Mbps
at virtually the same cost as todays 5 to 10Mbps networks, but without government
incentives, the very high speed services generally cost 2x to 4x what basic service costs.
Examples of how multiple tiers of bandwidth are being used to monetize the increased
capacity of an HSPA network and will be used with lTE networks include:
offers for bandwidth-based tiers of default service (1Mbps for $X and 10Mbps for $2X)
Turbo type services that provide higher bandwidth temporarily for a fee or as a reward
Peak/off-peak or time-of-day-based services that provide higher bandwidth in off-peak hours
Abuse control mechanisms such as reducing over-quota users to a lower bandwidth level in peak hours
From prioritization policies to tiering, the coupling of lTE with policy controls
promises to help resolve key economic challenges of mobile broadband while supporting
a new generation of services that elevate revenue and delight customers. The work
of the 3GPP in devising new standards for mobile data networking will leave a
lasting imprint on the industry and expand the boundaries of the possible in mobile
communications worldwide.
About Tekelec Tekelec, the session and mobile data management company, enables billions of people
and devices to surf, talk, and text. our solutions allow service providers to dynamically
manage network resources and services, while providing end users with a consistent
and personalized customer experience. We handle the complexity of todays multi-
generational and multi-vendor networks by enabling devices, protocols, services, and
databases to securely and efficiently communicate with each other. Tekelec has more
than 30 offices around the world serving more than 300 customers in more than 100
countries. For more information, please visit www.tekelec.com.
www.tekelec.com
Top Related