How Vodafone’s network infrastructure works
Vodafone’s network infrastructure is fundamental to the Group being able to provide mobile and fixed voice, messaging and data services. The Group’s customers are linked to the access part of the network, which links to the core network that manages the set-up of calls, transfer of messages and data connections and allows the Group to provide a wide variety of other services.
2G/3G mobile access network
When a voice call or data transmission is made on a mobile device, voice or data is sent from the device and transmitted by low powered radio signals to the nearest base station, which in turn is connected to the Group’s core network via the access transmission infrastructure. Each base station provides coverage over a given geographic area, often referred to as a cell. Cells can be as small as an individual building or as large as 20 miles across and each is equipped with its own radio transmitter and receiver antenna. This network of cells provides, within certain limitations, coverage over the service area. When a customer using a mobile device approaches the boundary of one cell, the mobile network senses that the signal is becoming weak and automatically hands over the call to the transmission unit in the next cell into which the device is moving.
Fixed broadband access network
When communication takes place over fixed line networks, the traffic flows over a traditional wired infrastructure until the point it reaches the Vodafone access device (a “DSLAM”), where it connects to the access transmission infrastructure. Additionally, corporate customers can connect their local network to Vodafone’s access transmission infrastructure directly using a dedicated link.
In the UK market, Vodafone delivers fixed broadband services through a reseller agreement with the local incumbent.
Access transmission infrastructure
The access transmission network is the connection between a base station, a DSLAM, or a corporate customer’s dedicated line, and the core network. This consists of mainly leased lines or Vodafone’s own transmission lines, such as microwave links.
The core network is responsible for setting up and controlling connections between mobile or fixed line customers attached to access networks by locating the called party and routing voice calls towards it. Additionally, the core network handles data traffic by allowing customers to access service platforms offering services such as Vodafone live!, web browsing, email, mobile TV and other data related services.
The core network comprises three domains, with each domain containing nodes with specific functionality interconnected by transmission links:
- The Circuit Switched domain enables voice and video calls. Its key nodes are switches (which manage the set-up of connections) and user databases, storing the information needed to provide services to each customer, such as location in the network, list of subscribed services and home/visited network.
- The Packet Switched domain allows customers to use data services. Its key nodes are responsible for a variety of functions, such as the delivery of data packets to and from mobile devices within a geographical service area, setting up data connections and providing the gateway between the Vodafone network and external data networks, including the internet and customers’ corporate networks.
- The IP Multimedia Subsystem (“IMS”) domain is the first step of a wider evolutionary path from the current core network to an all internet protocol (“IP”) next generation network. It enables delivery of advanced multimedia services, both mobile and fixed, leveraging the flexibility and effectiveness of internet technologies. IMS is expected to be a key element in the future infrastructure to support Vodafone’s total communications strategy, exploiting the technology of convergence between the mobile telecommunications and the internet world.
If the voice call or data transmission is intended for delivery to another device which is not on the Vodafone network in the same country, the information is transferred through a public or private fixed line telephone network or the internet.
Mobile network technology
Vodafone operates 2G networks in all its mobile operating subsidiaries, through Global System for Mobile (“GSM”) networks, offering customers services such as voice, text messaging and basic data services. In addition, all of the Group’s controlled networks operate General Packet Radio Services (“GPRS”), often referred to as 2.5G. GPRS allows mobile devices to be used for sending and receiving data over an IP based network, enabling wireless access to data networks like the internet.
The GPRS data service offering includes internet and email access, allowing the customer to always be connected at download speeds slightly below a dial-up modem. In some markets, Vodafone continues to further evolve data speeds with 2G evolutions beyond GPRS capability.
Vodafone’s 3G networks, operating the Wideband Code Division Multiple Access (“W-CDMA”) standard, provide customers with faster data access. Vodafone has expanded its service offering on 3G networks with high speed internet and email access, video telephony, full track music downloads, mobile TV and other data services in addition to existing voice and data services.
High speed packet access (“HSPA”)
HSPA is a 3G wireless technology enhancement enabling significant increases in data transmission speeds. It allows increased mobile data traffic and improves the customer experience through the availability of 3G broadband services and significantly shorter data transfer times.
High Speed Downlink Packet Access (“HSDPA”) has been widely deployed on Vodafone 3G networks at up to 3.6 Mbps (“Mega bits per second”) peak speed. In addition, starting in hotspots, the first upgrades to up to 7.2 Mbps peak speed have already started to be deployed in several operating subsidiaries. The figures are theoretical peak rates deliverable by the technology in ideal radio conditions with no customer contention for resources. This is providing customers with faster access speeds than historically experienced on 3G networks.
While HSDPA focuses on the downlink (network to mobile), Vodafone is also improving the data speeds on the uplink (mobile to network) with HSUPA (“High Speed Uplink Packet Access”). Operating subsidiaries have already started deployments to achieve peak speeds of up to 1.4 Mbps on the uplink.
Vodafone is actively driving additional 3G data technology enhancements to further improve the customer’s experience, including evolutions of HSPA technology to upgrade both the downlink and uplink speeds.
Current developments in the infrastructure
As growth in data traffic accelerates with the proliferation in, and adoption of, web services, Vodafone is evolving its infrastructure through a range of initiatives.
Access transmission infrastructure evolution
Vodafone is upgrading its access transmission infrastructure from the base stations to the core switching network as part of a transition to a scaleable and cost effective solution able to deal with the increasing bandwidth demands and data dominated traffic mix driven by HSDPA and fixed broadband.
Core network evolution
Vodafone has transformed its national transport networks in all subsidiaries, converging the infrastructure to support all services using IP as the strategic technology. During the 2009 financial year, the Group expects that the transformation to IP services will start to be extended to a European level, consolidating Vodafone’s ten national IP networks into a single IP backbone, centralising IP operations, avoiding duplication and achieving simplicity and flexibility to deploy new services to serve multiple markets.
While evolving the Group’s infrastructure, it is also important that the Group continues to have a tight control over its cost base. This has been achieved through various measures.
Significant effort has been placed in reducing the costs to deploy mobile network infrastructure. Important developments during the 2008 financial year included the extension of a tower sharing agreement in Italy as well as the formation of a company for the purposes of network sharing with other operators in India. Agreements have also been made on network sharing in Spain and the UK. Vodafone continues to investigate opportunities to share network infrastructure where it makes commercial sense based on local market conditions.
In 3G network deployments, Vodafone is driving the use of new technology enhancements such as “Remote Radio Heads” that are a new type of lower cost base station equipment, which improve coverage and enable improvements to the customer experience. In addition, all aspects of wireless access point site design are being targeted to reduce energy consumption.
Another type of innovation being considered by Vodafone is the potential for 3G femtocells to address capacity and coverage needs in certain network deployments. Femtocells are a new way to deliver 3G wireless coverage to a small area at low cost compared to traditional macro network technologies. Effectively, a femtocell would give a customer a small 3G base station connected to the Vodafone network via a fixed broadband line.
The scope of the Group’s outsourcing of IT application development and maintenance operations is expanding. Service commencement is now complete in all 12 selected markets of the first phase. The second phase of the project, principally outsourcing to India, is now in progress.
Vodafone has successfully completed outsourcing of its Indian IT estate to a specialist organisation with capability to match the Group’s scale and growth requirements.
In addition to the above initiatives, there are a number of IT cost saving initiatives that have been accelerated, which include the consolidation of European data centres and the outsourcing of internal help desks.