Vodafone Portugal proves the efficiency and profitability of migration from TDM to IP with Cisco Unified RAN Backhaul.
Challenge
Vodafone Portugal has been a leading example of transformation in the mobile network for years, demonstrating a keen insight and proactive preparation for what the world now acknowledges as a global mobile Internet revolution. Among its many achievements, Vodafone Portugal is also now the world's largest IP packet-based Radio Access Network (RAN).
Long before the growth of traffic from the popular Apple iPhone, Vodafone Portugal began preparing for an expected avalanche of mobile data traffic. In early 2006, the company took bold steps to begin the transformation of their RAN to reduce the recurring costs of leasing E1 lines that utilize time-division multiplexing (TDM) circuts to backhaul their traffic from cell sites to the base station controller (BSC) and radio network controller (RNC) in their mobile core. At that time, nearly half of the RAN backhaul was based on leased lines, which represented a huge expense.
In addition to working with their traditional radio vendors in ongoing technology readiness assessments, trials, and production deployments, Vodafone made the unorthodox decision to test the Cisco® RAN Optimization solution. The solution was a great success, doubling the backhaul capacity by using only two E1 lines to backhaul four E1 circuits per cell site, Figure 1.
Proof in hand, Vodafone Portugal added Cisco to the list of trusted mobile network advisors for their mobile transformation and began a full-scale production deployment of Cisco's RAN Optimization solution in September 2006.
Solution
Vodafone Portugal was aware that its users would contine to drive exponential demand in mobile data traffic, especially as mobile broadband and high-speed downline packet access (HSDPA), an enhanced 3G telephony protocol, began growing significantly in Portugal's urban areas in 2007. The company, therefore, continued to emphasize bold initiatives to increase capacity while controlling operating costs. The advent and popularity of Universal Mobile Telecommunications System (UMTS) HSDPA and the popular DLS access in Portugal's cities allowed Cisco to offer Vodafone a HSDPA offload solution. The solution uses the same Cisco UnifiedRAN Backhaul network framework and the same two leased E1 lines for backhaul, adding DSL backhaul, for a net optimization of seven E1 circuits and DSL backhaul using two E1 lines, Figure 2.
Figure 2. Cisco Unified RAN Backhaul Solution: Two E1 lines Backhaul Seven E1 Circuits and HSDPA over ADSL Per Cell Site
This solution made Vodafone Portugal the first and largest live, end-to-end IP-based mobile backhaul network in the industry. The company is further evolving its Cisco Unified RAN backhaul infrastructure solution to replace traditional leased lines with a Carrier Ethernet and Multiprotocol Label Switching (MPLS) network.
Cisco was selected as the technology provider following extensive network trials with Vodafone Portugal that demonstrated Cisco's ability to deliver a highly reliable IP RAN transport infrastructure to meet the ever-increasing demands of mobile Internet services. Cisco's Unified RAN Backhaul solution supports multiple mobile and radio subsystems from multiple third-party vendors, which was a key requirement for Vodafone Portugal. The solution is based on Cisco MWR 2941 Series Mobile Wireless Routers and Cisco 7600 Series Intelligent Services Edge Routers with Circuit Emulation over Packet (CEoP) shared port adapter modules, Figure 3.
Figure 3. Cisco Unified RAN Backhaul with Carrier Ethernet Architecture
Part of being an early innovator in migrating from traditional TDM networks to end-to-end IP involved some challenges for Vodafone Portugal. According to Jorge Fernandes, Vodafone Portugal's CTO, "Although the migration to Ethernet allows us to achieve considerable cost savings, it also poses the challenge of ensuring synchronization to our base station sites. Our cellular networks require accurate synchronization signals to minimize interference among sites and to ensure optimal inter-cell handover performance. The flexibility and robustness of the Cisco Unified RAN Backhaul solution, including synchronization, have proved strategically important for us as it can be used with any type of mobile traffic and is capable of supporting future 3G IP and 4G / LTE base stations as well."
To help ensure optimal cost savings and further reduce dependency, Vodafone Portugal put in a requirement that the new fiber-to-cell extensions must not rely on E1 or TDM access at the cell site. Another requirement was for clocking and synchronization to work without a Global Positioning System (GPS), because GPS would not be available for all sites. To meet these requirements, Cisco's Unified RAN Backhaul solution provides a means for timing over IP with an IEEE 1588-based solution. Cisco's MWR 2941 as a slave together with Brilliants C-2000, a carrier-class PRS/IEEE 1588v2 Grand Master from Brilliant Telecommunications, was validated by Vodafone's research and development department to meet all clocking and synchronization requirements, thus removing the only remaining technological reliance on TDM in the RAN.
The Cisco Unified RAN Backhaul Solution features include:
• Any radio, any media, many generations (e.g., 2G, 3G, 3G+, LTE)
• Radio neutral proven interoperability with all major radio vendors
• All IP advanced timing feature support (Sync-E and IEEE 1588)
• Optimal backhaul options (e.g., 2G and 3G optimization over TDM, HSDPA offload)
• High availability and redundancy all the way to the cell site
• Optional XaaS (everything as a service) wholesale service offering potential
• End-to-end quality of service (QoS) and service-level agreement (SLA) assurance that allows reliable third-party transmission options
• First to reach IP MPLS Forum certification, Metro Ethernet Forum (MEF) certification, and backhaul compliance
• References since December 2005
Results
Vodafone Portugal's advanced fiber-to-the-cell network will eliminate recurring leased line costs. It will also position Vodafone Portugal as a potential wholesale network service provider, enabling the company to lease capacity and leverage their network to offer other services, such as increasingly popular managed unified communications for businesses.
Vodafone Portugal's investment strategy is proving to be profitable. According to Vodafone's 2008 annual report, "The growth in adjusted operating profit of subsidiaries was primarily driven by increases in Portugal and the Netherlands of 20.2% and 13.2%, respectively, at constant exchange rates, resulting from the growth in service revenue, as well as good cost control in Portugal.... [The company saw] particularly strong growth in messaging and data revenue in the Netherlands and Portugal where new tariffs and Vodafone Mobile Connect data card initiatives proved particularly successful." And in Vodafone's 2009 annual report, the growth has continued: "The growth in EBITDA [Earnings Before Interest, Taxes, Depreciation, and Amortization] was primarily driven by increases in Portugal and the Netherlands of 12.3% and 7.9%, respectively, at constant exchange rates, resulting from the growth in service revenue, as well as good cost control in Portugal."
For More Information
Cisco Mobile Internet Solutions
http://www.cisco.com/go/mobile
http://www.cisco.com/go/mobile
Cisco Service Provider Solutions http://www.cisco.com/en/US/netsol/ns341/networking_solutions_service_provider_home.html
Vodafone Portugal
http://www.vodafone.pt
http://www.vodafone.pt
Vodafone Portugal 2009 Annual Report http://via.vodafone.com/etc/medialib/agm_09.Par.22820.File.dat/VF_Annual Report_2009.pdf