One needs to have a flexible platform in order to successfully deploy next generation networks since many issues can take hold during the initial stages of deployment.
EVOLVING STANDARDS
Industry standards that specify the technical features of the infrastructure equipment used in next generation networks are subject to change.
The 4G wireless standard for 3GPP LTE and EPC has recently been finalized and frozen, but just like other standards documents, it is open for revisions as spec errors are uncovered or implementation issues arise. In fact, the number of document revisions tends to increase dramatically around the time a standard is frozen because it is at this stage where active development of equipment begins, and with implementation of real systems, improvements and corrections are identified.
In the wireline domain, the standards for next generation Access and Metro equipment are even less mature than those for Next-Gen wireless. In the case of ITU-T Next-Gen PON, standards work has just recently begun.
INTEROPERABILITY ISSUES
In theory, adhering to industry standard specifications means that equipment produced by one supplier should operate seamlessly with equipment produced by another supplier. But in reality, it doesn't always quite work out that way. Many issues may lead to interoperability problems. For instance, the standards may not be fully complete which leaves room for interpretation; errors in implementation may occur which might be discovered only after interoperability testing; failure to keep up with standards revisions is possible and results in an obsolete implementation.
CHANGING CUSTOMER REQUIREMENTS
Sometimes customers cannot articulate what they really require, especially when it comes to new technology. As a result, implementation may be largely driven by technology push. But as early adopters discover the capabilities of the new technology, lead users provide important feedback to the manufacturers. Sometimes user innovation results in unanticipated applications of the new technology. Consequently, technology implementation undergoes further rounds of iterations or revisions, influenced increasingly by market pull.
Take for example the hugely popular (and very lucrative) SMS text messaging. Back when the GSM standards were being formulated, SMS was regarded by some to be an extra add-on. SMS is transported across the auxiliary signaling paths, which are low bandwidth channels normally used for control purposes (hence a 140 byte limit). SMS was initially not perceived to have much commercial value. Technology push was what brought it to the market. Fast forward to today and witness the popularity of SMS including novel applications such as Twitter, televoting (to cast a vote for your favorite American Idol) or SMS-enabled vending machines (so you can buy a chocolate bar for your BFF). Market pull now influences many SMS products, and features such as integrated platforms, increased capacity handling, address conversion, and distribution lists have been added.
Another example of changing customer requirements pertinent to 4G LTE wireless equipment is the shift from 2x2 MIMO support to 4x4 MIMO for higher bandwidth capabilities.
DISCOVERY OF PROBLEMS
Despite proper planning, insightful decision making, industry-wide cooperation and flawless execution, one still needs to be prepared for the unexpected when it comes to wide-scale deployment of new network elements. Faithfully simulating large-scale networks has its challenges and limitations. In addition, emulating all real-world situations and scenarios of a live network in a controlled lab environment is simply not possible. Issues will undoubtedly arise when new equipment is put live out in the field.
