Wi-Fi Design For British Land
About British Land
British Land are a leading European real estate investment trust. With one of the largest property portfolios in the UK, British Land focus on high-quality assets in sectors with long-term growth potential such as prime retail locations and central London offices. York House is a prestigious new development in London’s West End. Completed in early 2007 it has 93,000 sqft of retail space and residential units. British Land, the largest UK real estate investment trust with total assets under management of £21.4 BN, undertook the development and the building incorporates their new head office. British Land contracted affini to deliver a complete solution for the new building’s wireless network infrastructure.
British Land (BL) had some exacting demands for the wireless network that would permeate their new, purpose built corporate HQ, York House:
- A showcase system for a business building, supporting data & voice over wireless, for guests & company users
- Excellent – but secure – wireless data coverage in all customer and employee occupied areas
- A high-quality wireless infrastructure capable of acting as a core utility for the building, with a long lifetime
- Meet user expectations when using a wireless phone, with the same voice quality as a good mobile phone call
Whilst it was a new building, it was a challenging environment for wireless: 6 storeys with mixed occupancy. Floors 1 & 2 were to be let to tenants but wireless LAN service was needed on the ground floor reception and floors 3 to 5. There was to be no wireless leakage to the unoccupied parts of York House nor outside the building.
There was also a requirement to handle a specific – yet different – number of simultaneous voice calls per floor, plus the data users. A high-profile, critically important project, BL had high expectations of affini to deliver a solution: and get it right, first time.
An Integrated Approach
Adopting an ad hoc approach to more sophisticated wireless LAN projects such as York House, can result in project delays, over specification of equipment and more often than not the system not meeting the expectations of stakeholders.
affini however enables organisations to fully realise the benefits of wireless technology. Using an integrated approach that comprises consultancy audit, design, implementation, systems integration and management services, affini delivers high quality solutions via a five step cycle of best practice.
Creating a Wi-Fi Design
A Wi-Fi Design has three inter-related aspects: Radio Frequency, Physical and IT. Each must be addressed otherwise the applications running over the Wi-Fi network will not work as desired.
- RF – the foundation of a successful Wi-Fi network, covering the number & exact locations of Access Points, associated antenna types & pointing directions, power & channel settings.
- Physical – the build-related elements of a Wi-Fi network such as cable routes, antenna positioning and LAN cabinets.
- IT – creating a seamless, integrated solution via specifying network settings and supporting IT infrastructure.
affini’s design methodology for York House was built around three key stages:
- Capturing Customer Requirements: In this first stage affini carried out a thorough Requirements Capture to ensure any solution proposed would meet BL’s complete technical, commercial and operational needs, by analysing aspects such as coverage, mobility, throughput, latency & user access arrangements.
- Site Survey & Audit: Next, a highly accurate data capture exercise precisely measured the site’s RF propagation characteristics, establishing and locating potential sources of interference; it also assessed the building characteristics to identify any radio, equipment or implementation issues or constraints.
- Detailed Design: Then, accounting for all aspects of BL’s requirements, affini produced a comprehensive report of all the RF & Physical Wi-Fi aspects, including plots of predicted throughput and coverage for each AP. The RF design used affini’s Red-Predict software, which takes the audit data as a baseline to help ensure the most accurate, high quality wireless design possible.
Enabling the Wi-Fi Network
Finally, a complete design for the Wi-Fi IT aspects: to meet the requirements of corporate roaming data users, wireless VoIP telephony and guest user internet access; and integrate the new Wi-Fi system with the existing BL corporate network.
affini’s network design had 25 Cisco APs with external antennas, connected to LAN switches on BL’s corporate data network. affini specified all wireless system settings including Quality of Service, security and LAN switch configurations. It also proposed that traffic on the Wi-Fi network should be segregated by function, using 802.1Q VLANs on the Aps and LAN switches – this allowed different wireless and fixed network settings for each user service facilitating easier, more flexible network management and security.
BL’s combined requirements for capacity, coverage & quality presented an extremely difficult design challenge because it meant careful planning of the AP coverage overlaps (to achieve efficient cell handover for voice and sufficient data throughput) whilst managing any potential interference – but affini was up to the task, creating a design that fully met the requirements.
VLAN’s & Security
The VLANs proposed were as follows:
- Management VLAN for managing the APs; this would be unavailable to wireless clients
- Voice VLAN with appropriate QoS settings for the wireless telephones constraints
- Data VLAN for conventional wireless data access by wireless computers and handhelds
- Guest VLAN for guest access to the public internet and e-mail
Each wireless VLAN has its own SSID to uniquely identify the type of service by mapping a client device onto the correct VLAN on the wired network infrastructure. The security settings recommended were:
- Voice VLAN – WPA2-PSK (Pre-Shared Key), to ensure the minimum re-authentication delay when a voice client roams from one AP to another
- Data VLAN – WPA2 with RADIUS Authentication
- Guest VLAN – free association at the AP with user sign-on using a web based internet portal
affini then embarked on delivering a complete turnkey solution, taking on total network design accountability.
This final phase included:
- Total system project management service, interacting with other suppliers (cable contractors, builders, handset supplier etc.) and BL IT personnel
- Supply of all required hardware
- Pre-staging the Wi-Fi equipment, programming and testing the complete system prior to deployment on site
- Physical installation of APs and external antennas
- Integration into the corporate data network, with commissioning and final configuration of Aps
- Post-installation RF Testing to measure the achieved coverage of the Wi-Fi network, to show it fully meets the network requirements
- Acceptance testing via subjective data and voice tests using client devices, to confirm that the network delivers the required user experiences
affini ensured this high profile project was delivered on time and to budget. It has met the stakeholders’ requirements and is delivering the excellent user experience that we wanted. We are very pleased with affini’s work – they got it right, first time. Jay Hunter, Group Infrastructure Manager, British Land
- CATEGORY Consultancy