The once revolutionary WiMAX may soon be overtaken by competitive technology. Hence, the time needed to deploy a WiMAX network and the available lead time for adoption will prove crucial to its success. However, operators' expectations, limitations of a certification lab and lack of a WiMAX forum endorsement for deploying certified products have all resulted in a pipeline of almost a whole year before a 802.16e product is rolled out.
What a WiMAX operator needs is a risk mitigation strategy to carry pre-compliance tests, in order to ensure a faster turn around. Here are tips and tricks of a risk mitigation mechanism called 'Remote testing,' that enables WiMAX equipment manufacturers to test their equipments onsite using an intuitive web-based graphical user interface.
Conventional mechanism
While spectrum auctions and the quick emergence of WiMAX service providers suggest a rapid rollout of new WiMAX networks, deployments are still dominated by proprietary equipment. Manufacturers are racing to develop new products and eliminate the costs involved in compliance testing to reach the market faster. In order to have seamless services across the networks and vendors, the WiMAX forum has passed a mandate to deploy certified products that are echoed by operators too. Hence certification is the conventional way to rollout the products.
Presently, there are 10 certification labs endorsed by the WiMAX forum spread across the world in countries such as Brazil, China, India, Korea, Russia, Spain, Taiwan and the USA,. The complete WiMAX certification process involves two stages:
- Compliance testing to ensure that the product complies with the system profile's test specifications
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- Inter-operability testing (IOT) to ensure that subscriber units and base stations from different vendors operate within the same network.
This testing is performed in a WiMAX forum endorsed lab so the vendors are required to physically ship their products to the respective lab. If the equipment fails to comply with system profile then the whole process needs to be repeated again. The overall process can be time consuming and costly
Risk Mitigation Mechanism
The first hurdle before deploying a WiMAX network is Certification
Certification is a time consuming and an ongoing process and its scope changes as features are added with each upgraded profile. Vendors have a different approach towards certification. Their approach reflects their marketing strategy, product timeline and overall resource availability.
To make matters more complicated:
- End-to-end IOT specification has not yet been defined
- Certification labs only provides air interface certification
After Certification, we can proceed towards deploying the network. Deployment is a complex and tricky process which involves a complete understanding of the business case for WiMAX.
- Vendors have to address various deployment challenges which are unique to a particular geography
- For Ex: Efficient use of the allotted spectrum in a country like India is of prime importance
- Another issue which needs to be addressed is whether to deploy the network for optimum coverage or high capacity
- Future proof the network--Network would be required to support an eventual migration to mobile WiMAX
- Commissioning of the core and backhaul network
- Accelerate commissioning of test & commercial network
Considering these challenges what are the tricks to ensure an efficient network rollout?
It is important to perform interoperability testing before commercial deployment.
Vendors need to benchmark network coverage and capacity capability through test labs and other Industry accepted channels. It is also a good practice to incrementally integrate the network elements starting from the core and gradually moving towards the access network
Why Remote Testing?
WiMAX remote testing enables WiMAX OEMs to test the compliance of their equipment against the key scenarios of the WiMAX Forum's Network Working Group (NWG) Wave 1 standards. This can be done on the customer's premise over a secure link. Remote WiMAX testing offers several key features that address the challenges of conventional testing method:
- Remote testing of the R6, R4, and R2 interfaces over the Internet and onsite premises
- Customized off-the-shelf NWG compliant scripts for different system profile available
- Pre-certification testing to avoid failure in the WiMAX forum endorsed certification lab
- Access to interoperability testing
- Access to a pseudo lab set-up comprising of BS Simulator, ASN GW, AAA, HA, BG and so forth
Remote service can be used through an intuitive Web-based graphical user interface. The test tool can assess the behavior of an Implementation Under Test (IUT) according to pre-written tool command language (TCL) test scripts based on the test plan. This helps network equipment manufacturers identify standards compliance issues enabling the smooth introduction of WiMAX networks.
Remote testing provides an opportunity for WiMAX vendors to verify NWG compliance onsite and with security and convenience, ensuring hassle-free product certifications, while reducing costs and accelerating time-to-market. It is key for operators and vendors to be aware of the main challenges of WiMax to appropriately address and certify their WiMax services.
About the Author
Ajay Gupta is the Vice President of Aricent's Wireless and Convergence strategic business unit since early 2006. Since May 1997, Ajay has been playing a significant role in developing the telecom business at Aricent in such fast growing segments as 3G/UMTS, the IMS, and Voice over Internet. Ajay is an active member of various industry bodies and is actively involved with the SIP Marketing Working Group to promote SIP and bring together the various organizations working on SIP.
He is a B.E. (Hons), Electronics and Communications, from Punjab Engineering College, Chandigarh, India. He can be reached at: Ajay.Gupta@aricent.com
