US : As third-generation (3G) networks reach mass deployment in countries around the world, the industry is aggressively working on the deployment of Long Term Evolution (LTE) and the transition to fourth-generation (4G) mobile. Catapult Communications, a leader in digital telecom testing, is part of this evolution to 4G, helping drive advancements in network performance, technologies and services. The company has defined four best practices in testing critical to service providers during this transition.
“The mobile industry needs to ensure that 4G and LTE technology is not hampered by the problems that beset earlier 3G network rollouts. Operators cannot deploy too early and test tools must be more flexible, more powerful, easier to use and more economical,” said Adam Fowler, Vice President of Catapult. “The entire test community must play a vital role in the successful development of these technologies.”
3G and 4G-based applications are all designed to address growing consumer demand for rich services and connected lifestyles supported by high-bandwidth multimedia applications. The underpinnings of the next phase of 3G networks are LTE radio access technologies enabling faster data speeds and new services. Operators deploying LTE will benefit from having a simple upgrade path from 3G networks to increase capacity, reduce network complexity and lower deployment and operational costs. Standardization work on LTE continues with widespread support from device vendors, infrastructure vendors, operators and key industry associations such as 3 rd Generation Partnership Project (3GPP).
In 2009, operators are planning LTE network trials. At this inflection point, a few best practices warrant consideration to help LTE networks deliver the promise of a true mobile broadband experience at deployment.
Enhance Collaboration in the Value Chain
While a majority of the test community’s business is with original equipment manufacturers (OEMs), operators are a key constituent. With LTE, members of the test community must be willing to work differently by partnering across the value chain with OEM’s, operators and even other test companies. Ideally, test companies will be integrated into two critical paths, the OEM’s development processes and during the installation and support of equipment in operator networks.
Test Early Versions of Standards
Much of the progress and testing for LTE has been around the physical layer which involves technologies such as OFDMA and MIMO. Layer 2 and Layer 3 protocols are also being tested on both the eNodeB and the core side. Though LTE specifications have been approved for 3GPP Release 8, some adjustments will likely be made in the coming months. Test providers can help bridge the gap until standards are stable by implementing customer proprietary protocol variants.
Concurrent, 360 Degree Testing
eNodeB should be tested from all sides concurrently with comprehensive testing to simulate realistic network scenarios and user traffic, and ensure interoperability with existing UMTS and GSM networks. This demands a wrap-around testing configuration including new LTE nodes and new testing solutions. The eNodeB must be surrounded from the radio side in order to capture critical protocols (RLC/MAC) that were available before on the core side of the nodeB in UMTS. Today, LTE testing is taking place at the core side of eNodeB as well as the user plane with new encoding on the air interface, new security and higher bit rates. A greater emphasis is called for on testing the user plane, validating the user plane traffic and the associated protocols as the industry evolves into full IP data communication. This approach is needed to safeguard and enhance the quality of services and user experience, which is critical and will ultimately be the key driver in accelerating demand for LTE services.
Improve Network Handoffs
A key issue with previous 3G deployments was problems with handoffs, especially between network technologies. The same challenge is inherent with LTE, therefore a multi-technology test environment is necessary to vigorously test all specified handoffs.
In 2001, operators encountered technology problems with 3G deployments because product development was based on a pre-standard version of 3G. The launch of 3G primarily started in 2003, and on a global basis developed full momentum in 2005. Six to seven years after the standards were finalized, deployments and user penetration increased worldwide but operators are still far from recouping their investments.
