In June 2004, 3GPP Release 5 introduced the Policy Decision Function (PDF). PDF was initially a small part of the P-CSCF (Proxy Call Session Control Function) that correlates subscriber signaling sessions and bearer sessions. It was redefined and enhanced in Release 6 by separating from P-CSCF to become a standalone entity. In Release 7, 3GPP combined PDF and CRF (Charging Rule Function) to form PCRF (Policy and Charging Rule Function). PCRF is widely deployed in today's MBB networks.
Other standards organizations, such as ETSI, WiMAX Forum, and PacketCable, have defined standard architecture for policy management tools for different types of networks. ETSI's FBB network policy function is RACS (Resource and Admission Control Sub-System), while the WiMAX Forum and PacketCable's network policy tools are both known as PCRF. The network architecture and interface protocols of both these latter tools are consistent with 3GPP standards.
3GPP has greatly influenced the development and maturity of policy management tools, and most products adopt its standards. According to Infonetics, the global policy management market in the wireless and fixed markets in 2015 were worth close to US$1.5 billion and US$1 billion, respectively. Most recently and already accepted by the industry, 3GPP Release 12 and 13 define policy management methods and network architecture protocols for 3GPP networks (2G, 3G, and LTE) and non-3GPP networks (FBB, Wi-Fi, CDMA, Cable and WiMAX), covering terminals, pipelines, cloud applications and services, and unified policy centers for multiple access networks.
Policy management tools can dynamically configure network resources on a per user and per service flow basis. Network resources include MBR, QCI for access prioritization, pre-emptive ARP, data use by subscribers, and switching the charging mode between online and offline.
For some time after 3G networks were rolled out, the lack of content was failing to use operators' 3G data networks effectively. This changed with the advent of Apple and Android phones and the OTT revolution they started. Content would no longer be a factor that limited the development of mobile networks, and operators were able to use policy decision functions to convert voice subscribers into 3G data subscribers.
Unlimited bandwidth with speed limits: In 2012, AT&T was forced to withdraw the unlimited broadband plan it had released two years earlier, because its network lacked a policy management system and couldn’t handle the traffic increase. In 2016, it launched a new unlimited package, this time embedded with policy management. Subscribers can enjoy unlimited speeds as long as they don’t use more than 22 GB of data, after which speed is throttled.
This type of policy is also widely adopted by carriers in Europe and the Middle East. Saudi Arabia’s Mobily has marketed an LTE tariff for business users that offers a similar bandwidth policy to FBB plans, which helped the operator quickly lead the market.
Bundled policies for devices: After deploying their 3G networks, China’s big three operators began promoting plans with bundled high-end smartphones, such as iPhones or Samsung handsets, if subscribers sign up for a two-year data plan.
Family quota policies: In Norway, Telenor released a multi-user shared quota policy that spans multiple devices or brings in family members under a large data plan. Six months after launching this plan, 20 percent of Telenor's existing data subscribers had signed up.
Management policies on charging rules: In the UAE, du’s policy control system for billing rules and quota management on its 3G network gives an offline charging policy for within-quota subscribers, passing usage information to the policy control system. When the quota is reached, the policy control system instructs the gateway to switch to an online charging policy. The gateway then interacts with the OCS (online charging system) to execute PAYG charging. This means the growth in data services won’t be restricted by the charging system, and slashes investment in charging systems.
VoLTE quality assurance policies: VoLTE services are currently being rolled out around the world. Policy management makes it possible to establish dedicated transmission pipelines for VoLTE services, thus guaranteeing the quality of the network experience for HD audio-visual services on VoLTE.
When it rolled out its FBB network, China Telecom first offered plans with data usage quotas. For example, subscribers could purchase a certain amount of data for a set price, for example, 200 MB for 30 yuan. But, this failed to significantly increase subscriber numbers, so the operator quickly switched to an unlimited data business model. Differently priced plans offer different speeds – 1 Mbps, 2 Mbps, and 8 Mbps – but data is unlimited. While this kind of FBB network model partly reduces the need for policy management, it’s still required.
Limiting heavy users: Telefónica Deutschland leases the last mile of its FBB network to other local operators, charging them for bandwidth used and limiting access speeds for bandwidth hogs who use more than 100 GB per month on its fixed-line network. Ethio Telecom currently offers data usage plans for its FBB network, and has seen a slow rise in subscriber numbers. It plans to launch unlimited data usage plans in 2016 with a speed limit. International traffic creates the majority of Ethio Telecom's subscriber bandwidth, meaning the carrier must pay international operators, which makes a policy decision function essential to avoid losing money when offering unlimited plans.
Accelerating 4K intelligent bandwidth: 4K video technology is proliferating, but there’s a distinct lack of 4K content. Subscribers are reluctant to pay for high bandwidth speeds like 100 Mbps just to watch 4K video when they don’t need it for other services. A number of subsidiaries of China Telecom and China Unicom have deployed commercial policies for intelligent bandwidth acceleration, so subscribers can increase access speeds temporarily if needed.
Many operators are opting for fixed-mobile convergence, including Kenya's Safaricom, Mobily, and Indonesia's Indosat, all of whom are busy constructing FBB networks. Converged operators can greatly enhance subscriber satisfaction with cross bundles offered under policy management solutions. China Telecom began offering integrated bundles in 2010, with its E8 and E9 plans providing different types of Internet access methods, including MBB, FBB, and Wi-Fi, to give subscribers a consistent online experience across different network types.
The rapid growth in broadband networks has helped service virtualization and cloud services emerge and, with the appearance of important computing services such as cloud services and big data, the industry has turned its gaze to SDN. SDN enables much finer control of a network with the logical and comprehensive policy management of sessions, subscribers, devices, and application layers. SDN networks execute different routing policies depending on application type, and the system can choose the optimal path for forwarding packets by determining the level of traffic on network nodes in advance.
With the evolution of network architecture from standards organizations and the growth in network services, unified policy centers need to manage multiple access networks, including MBB, FBB, SDN, and Wi-Fi. They must also deliver a consistent, optimal experience for subscribers. As well as unified network access, policy management can also enable services for subscribers on devices and content providers on the cloud.
Policy management tools now provide subscriber services via a real-time communication channel.
Subscriber notifications: Policy control systems can issue real-time notifications to subscribers in various ways, including SMS, web pages, and toolbars. These notifications, for instance, might encourage subscribers to buy more traffic when they’ve used up their quotas, or provide information about roaming charges and information about their plans when they roam.
Real-time precision marketing: China Mobile uses the real-time notification function of its policy management system as a major marketing channel, and has developed many marketing policies. For example, when subscribers approach a China Mobile store, they might receive a notification telling them they can upgrade to a free USIM card, or a news app might push a text message for signing up to China Mobile's charge-free mobile news service. China Mobile has increased its marketing success rate by more than 30 percent thanks to this type of precision marketing.
Fast service acquisition: The UK’s EE uses a policy control system to analyze users' SMS content and determine the type of plan subscribers want to sign up for. It then notifies the BSS to start charging when they do. Subscribers can sign up to services wherever they’re connected, greatly enhancing user satisfaction.
Access network selection: Most mobile carriers operate a number of networks including 2G, 3G, LTE, and Wi-Fi, all of which may experience different levels of traffic at any one time. Policy control systems can manage subscriber network access based on a range of conditions. On Ooredoo Kuwait's network, for example, heavy LTE users who use more than 30 GB of data per month are offloaded to the 3G network to avoid congesting the LTE network.
Policy management can enable OTT content cooperation and management, helping operators to develop new market opportunities.
Network bandwidth capability opening (OTT cooperation): Under paid terms, China Telecom has opened up subscriber bandwidth management capability on its policy management system to third-party OTT provider Xunlei, whose VIP users can get 100 Mbps bandwidth speeds when downloading content.
Content bundling policies: Movistar Chile offers different plans such as Mail + Chat, Redes Sociales, and Navegación, so subscribers can access different types of content. By leveraging an OTT vendor's huge customer base, operators can boost subscriber numbers.
Continual improvements are being made to these systems in terms of policy deployment. Unified policy operation platforms and marketing language can configure policies and automatically generate and issue different scripts for policy configuration, accelerating service TTM.
By 2020, there will be 7 billion Internet subscribers, 100 billion connections, and 40 exabytes of data used per month. To take full advantage of the value of this coming explosion in data, operators will need a unified policy center to provide subscribers with an optimal, seamless experience across networks.