Five Steps for Deploying Broadband Wireless Access Networks
Today's global business and residential users are demanding higher bandwidths at affordable prices to support faster, processing-intensive Internet applications. More important than bandwidth is the need for higher network availability and increased reliability.
One promising solution to meet these increasing user demands is a wireless technology known as Broadband Wireless Access (BWA), better known in the United States as Local Multipoint Distribution Service (LMDS). The potential for BWA to become a valid competitor to DSL and cable modems as well as other wired transport medium is evidenced by the number of licenses and planned operators. In the United States, more than 400 licenses have been awarded to companies planning to offer BWA. While North America constitutes a sizable market, it is estimated that two-thirds of all BWA networks will be deployed on other continents with an estimated total product market of $3 billion (USD) by 2005.
The successful commercialization of BWA and its seamless acceptance by both business and residential users requires significant infrastructure cost reductions. The more established infrastructure vendors may soon be surpassed by new entrants such as Galleon Wireless Corp., based in Milpitas, Calif., that have taken advantage of key packaging and RF technologies to reduce costs by upwards of one order of magnitude. As the prices come down, supply and demand should significantly increase from the licensed operators driving a more rapid and efficient deployment of BWA networks. Beyond economics, the success of BWA technology depends on efficient deployment planning. Without it, operators may find themselves with schedule delays, non-optimal networks and personnel sitting idle waiting for the delivery of infrastructure.
Figure 1. A point-to-multipoint hub for BWA communications from Galleon Wireless Corp.
This article introduces the fundamentals of BWA and reviews a proven program management process which has been used extensively in the wireless industry to successfully plan, deploy, commission, test and commercialize networks worldwide. By following this program, BWA operators, supported by experienced technical personnel, should be capable of meeting the expected demands for higher, faster and more reliable bandwidth. Selecting BWA will enable operators to keep pace with customer needs cost effectively over the next several years, whether they modernize old infrastructure or deploy networks where none existed before.
Since the first license was granted in 1991, BWA technology has proven to be an ideal complement to fiber, offering a fixed, effective and wireless "last mile" solution both technically and financially. The advantages of BWA stem from its ability to deliver higher bandwidth at high fidelity, quickly and cost effectively.
BWA uses high frequency microwave signals, typically ranging from 24 GHz to 42 GHz, to send and receive high bandwidth digital data (voice, video, Internet, etc.) wirelessly between two fixed line-of-sight (LOS) points. Subsequently the equipment at these points can redistribute the same signal and bandwidth to other points simultaneously (i.e. multipoints) through a "hub-like" network.
Another characteristic of BWA is the fact that the output power of BWA transceivers (or Outdoor Unit, ODU) is significantly lower in comparison to cellular and PCS base stations. BWA ODUs operate with an output power of approximately 1 watt versus 50 to 100 watts for typical mobile wireless voice networks. Unique to BWA systems is an Indoor Unit (IDU) that monitors and controls the ODU via a serial connection to a digital modem. These ODUs utilize a technique similar to industry's proposed Software Defined Radio, which defines and causes the download of the required modulation scheme to support the user demanded bandwidth.
Figure2. An Outdoor Unit (ODU) for BWA communications from Galleon Wireless Corp.
Despite its positive attributes, BWA has some inherent challenges. One worth mentioning is that BWA networks are attenuated by water droplets (rain, fog, mist and snow). However, proper program planning and optimized deployment based upon projected user demands and taking into account environmental conditions will minimize these challenges. As an LOS network, BWA transceivers are also usually mounted on building rooftops, minimizing the effects of multipath, fading and attenuation. Other challenges include maximizing the coverage area (or cell size) by utilizing a link budget based upon the desired signal availability and quality (typically ranging from 99 to 99.999 percent).
Compared to other wireless networks, entry into the BWA market has lower infrastructure, ancillary and deployment costs. Measurable cost savings have already been achieved by several small market operators. These operators are using their licenses to deliver point-to-point high bandwidth service as opposed to deploying (or ordering) more expensive and complex fiber systems (for T1 or T3 service).
Minimizing deployment costs is critical to financial success since these costs alone may exceed the cost of the infrastructure, especially with "greenfield" deployments. One way to reduce deployment costs is by providing proper training to the field staff that encompasses installation, commissioning, troubleshooting and optimization. Fortunately, BWA equipment is designed to be simple, robust and easy to install and operate. Size reductions in BWA packaging as well as highly integrated functionality allow BWA networks to be deployed quickly, easily, efficiently and effectively. On a recent deployment at an international location, installation and commissioning of an ODU/IDU pair was accomplished in less than 4 hours by one field technician as compared to two days by two engineers for cellular and PCS base stations. Such rapid, efficient and trouble-free deployment of BWA infrastructure enables the operator to realize revenue faster than other types of high bandwidth wireless or wired networks.
Another inherent financial advantage of BWA is that equipment infrastructure supplies are strictly demand-based as opposed to a typical launch strategy for most wireless systems where operators hope to lure a customer base that will provide a return on investment within a reasonable timeframe. With BWA, operators are not required to order, stock, depot and deploy large amounts of infrastructure and personnel in areas that may not require coverage. Building on demand is financially attractive and minimizes capital expenditures. These cost savings for a demand-based model apply to equipment as well as the personnel required to deploy it. Outsourcing the deployment costs to qualified contractors can provide significant cost savings by minimizing payroll costs for full-time employees.
The speed of BWA deployment also minimizes deployment costs. For example, a point-to-point fiber network between high rise buildings several miles apart might require several months to install and be available for operations. However, a BWA network could easily be installed in a matter of days and be operationally available months in advance of the fiber network. The lost opportunity costs as well as increased labor force (from technicians to schedulers to material handlers, etc.) clearly show the advantage of BWA networks.
In addition to deployment costs, on-going Operational, Administration, Maintenance and Provisioning (OAMP) costs are sharply reduced because of the simplicity and integration of BWA infrastructure. Existing BWA systems require minimal maintenance and control and can readily be integrated into existing infrastructure Network Management Systems (NMS). Remote monitoring of the equipment as well as the environment can provide advanced notice for repair and maintenance. Most BWA equipment such as the ODU and IDU are designed as field replaceable units making troubleshooting and repair by field technicians much easier.
BWA Network Equipment
A typical BWA network consists of four primary system components Network Operations Center (NOC), Switch and Transport Infrastructure, Hub Fiber Interface and Customer Premise Equipment (CPE, i.e. the ODU/IDU pair).
The NOC is the operator's facility that integrates the hardware and software and performs network management functions (sometimes called NMS).
The Switch and Transport Infrastructure includes the fiber base (SONET Optical Carrier), backhaul (central office equipment), switching components (ATM and IP switching systems) and all interconnections to the Internet PDN (Packet Data Network) and PSTN (Public Switched Telephone Network).
The Hub Fiber Interface includes equipment that provides the wireless network's interface to fiber, performing the conversion from fiber to wireless and vice versa, as well as all modulation/demodulation schemes and microwave transmissions.
The CPE is a combined ODU and IDU which performs all RF functions and wireless transmissions. At times an operator's customer may take delivery of the CPE and perform the installation on their own or retain the operator to do so.
Efficient, timely and cost effective BWA network deployment can be readily accomplished through structured project planning led by program management. Program managers need to take into account requirements from all team members including marketing and sales, finance, business, product development, engineering, network planning and customer support. They must approach the project with an understanding that a license was purchased to operate a BWA network and it is critical that return on investment be expeditious without sacrificing quality.
The following summarizes a proven five-step process in successfully planning, deploying, integrating and operating a BWA network. The five-steps are:
Planning, Ordering and Logistics
Engineering, Installation and Commissioning
Cutover and Acceptance
Step 1: Planning, Ordering & Logistics
Successful deployment of any wireless network requires the up-front use of proven program management techniques by experienced managers and planners. Key areas to define, implement, track and manage are:
Customer Communications and Logistics
Project Financials (Resources, Cost, Logistics)
Equipment Warehouse Logistics
Equipment Ordering and Manufacturing
Design and Engineering (RF, Backhaul, Network, Database, Hardware)
Deployment and Sustaining Plan
Site Access, Audit and Engineering
During this phase, key deliverables are required to drive future requirements and plans. These deliverables include:
Network Design Document
Preliminary RF Plan
It is crucial that the assigned program manager becomes a visible and vocal leader orchestrating the above tasks. Managing these tasks and ensuring that the deliverables are timely, accurate and documented will only support future implementation activities. Close coordination and daily communication with the entire project team is necessary for smooth deliveries and deployments as well as quickly resolving any unplanned problems. A program manager's tool suite should include a master plan with a project schedule, budget and clearly defined set of roles and responsibilities for all key managers and functional organizations. Daily meetings are typically required as are action item ledgers that track the assigning and subsequent completion of open tasks. Clear, adaptable leadership with well communicated goals are the key to the success of Step 1.
Step 2: Engineering, Installation & Commissioning
Although Step 1 initiates the deployment plan, it requires constant update and modification to incorporate the latest information and plans. The next logical step after Planning, Ordering and Logistics is Engineering, Installation and Commissioning.
Successfully engineering a BWA requires close coordination with engineers and technicians in the field as well as the manufacturing and test equipment organizations. This includes site, installation, test, RF, network and transport engineers. Critical to this stage of deployment is up-to-date information from client locations to best assess the status of site acquisition, site preparation and interconnect readiness. In addition to field installations, commencing training for customer personnel should start at this phase. Hands-on support and involvement by customers is key to their acceptance of the equipment and ultimate signoff. Also, defining and creating the necessary databases to provision and operate the network is expected at this time.
Key areas to define, implement, track and manage are:
Customer Support and Training
Database Builds and Audit
Installation, Commissioning and Acceptance
During this phase, key deliverables are required to determine operational readiness and test. These deliverables include:
Site Audit Checklist
Site Ready Checklist
Installation and Commissioning Plans and Procedures
Acceptance Test Plan
The accuracy and timeliness of the deliverables is important since these documents will be used for customer witnessed site audits, equipment installations, software commissioning and acceptance testing. Also, the customer may use these documents to implement their frequency and backhaul plans with other vendors.
Step 3: Integration Test
Engineering, Installation and Commissioning is followed by Integration Test, where BWA infrastructure is combined with other systems such as interconnects, network management systems, billing, databases and several other adjunct services.
During this phase of the program, management must carefully maintain a step-by-step process to implement the test plans and procedures. This requires close coordination with the field staff in documenting accurately and precisely the performance levels of the BWA equipment. This also requires a methodical approach to troubleshooting and resolution. When necessary, the field team may require the support of design engineering from any of the suppliers to resolve an open issue or clarify documentation and system performance. Tracking problems and resolutions will determine the final punch list that the customer will subsequently approve or disapprove.
Key areas to define, implement, track and manage are:
During this phase, key deliverables are required to determine readiness for system integration and test. The key deliverable includes:
Integration Test Plan
Open and frequent communication, whether verbal or in writing, is a must during this phase of the project. Having customer support to help resolve issues also is important since the customer must ultimately be satisfied with the performance level of the infrastructure.
Step 4: Cutover & Acceptance
To finally reach the state of commercial readiness, this stage in the BWA deployment process requires cutover into a normal mode of operation and acceptance of the delivered and operational system. Step 4, Cutover and Acceptance, is the final step in completing the deployment. It also includes system optimization. During this phase, the program manager must maintain close watch over system testing, including customer hands-on training and operational support. Documentation must be updated and accurate so that customer personnel feel comfortable with the operations and maintenance of the equipment. They must also have a complete understanding of how to implement escalation procedures. The field team must begin relinquishing the equipment and transition operations to the customer so that conditional/final signoff and acceptance can occur.
Key areas to define, implement, track and manage are:
Acceptance and Signoff
Post-Cut Site Integration
During this phase, key deliverables are required to determine readiness for cutover to normal and customer-led operations. The key deliverables include:
Performance Evaluation Reports
Conditional Acceptance Report
Final Acceptance Report
Close coordination with the customer is a key to system signoff. Accurate and detailed reports that summarize performance as well as status are conducive to cutover and acceptance. The program manager must complete this final stage of deployment with exuberance, knowing that the deployment portion of the project is coming to completion.
Step 5: Sustaining
After completing system signoff and acceptance, the BWA network is ready for commercial operation and revenue can be generated from operator clients. During this on-going stage of the deployment, the program manager is responsible for bringing closure to the project, fulfilling any final obligations for deliverables and removing and de-installing any unnecessary and non-customer related equipment.
Key areas to define, implement, track and manage are:
Project Management Closure
During this phase, key deliverables are required to track on-going BWA system performance. The key deliverables include:
Operations and Performance Reports
With the completion of the project and transition to sustaining operations, the project is brought to a close.
The methodology described above can be complex and difficult, yet with experienced personnel dedicated to using proven wireless network deployment techniques, BWA operators can be assured of a successful, revenue generating and cost-savings deployment.
Robert Sanchez is with inCode Telecom Group (www.incodetel.com ), founded in 1998 and headquartered in La Jolla, Calif. inCode is a leading provider of engineering, program management and technical services consulting to companies shaping the future of telecommunications around the world.