Most existing powerline vendors believe that their market success is highly dependent on their ability to create products that can reliably operate within this coveted frequency range. As a result, a scramble to capture the heart of this spectrum is beginning to take place within the powerline industry. Unfortunately, as vendors and consortiums seek for frequency space, some are blind to the damage done to the powerline medium itself. The current challenge isn’t about developing applications around a specific technology – it’s about preserving the integrity of the medium to avoid potential problems between technologies vying for the same frequency.

Powerline is a ubiquitous medium and is inherently attractive for networking a large expanse of consumer products in four basic categories: control, data, multimedia and “last mile.” Typically, powerline devices are designed to address a specific market category, but do not scale well into other categories. This results in numerous technologies occupying the same frequency spectrum, on the same wire, each supporting a different set of applications.

1)      Control Networks: Traditionally lower cost and lower speed, these applications have a long existence and will continue to increase penetration. This segment cannot be ignored, but is untouchable by more elaborate, higher cost solutions.

2)      Data Networks: Bursty traffic, high speed and reasonable costs drive this category. These applications try to drive as much information onto the same medium as they can, in a non-deterministic fashion. Unfortunately, this non-determinism is not conducive to multimedia traffic.

3)      Multimedia Networks: QoS and scalability are the primary hot buttons here. These applications need guaranteed latency, bandwidth and prioritization. Technologies developed for control or data application typically do not scale well into multimedia networks.

4)      Last-Mile Networks: Last-mile networks utilize the powerline to send broadband streams to the home from a service provider. They must be capable of hosting and routing various services, so flexibility and high bandwidth are critical.

With the wide array of applications on the powerline and companies seeking to develop silicon for these applications, it is easy to see why several technologies may dominate, contention for the medium may exist and why a resolution must be found. Imagine driving a vehicle into a busy intersection designed by different contractors, with intersecting roads sending traffic through at different rates using different rules. One road may require short stops for small, high-speed motorcycles. Another road may require long stops for lumbering, slow-moving trucks. Yet, other roads may follow entirely different rules, servicing small bicycles, large buses or other forms of transportation. Without some type of traffic control, imagine the frequent collisions, chaos and ultimate traffic jam likely to occur at this intersection.

Powerline Q&A

So, the question must be asked: can Powerline vendors get along and still compete? How do vendors collectively free up traffic and still maintain a competitive marketplace? The answer: the industry must embrace Powerline co-existence through a concerted and purposeful effort. Powerline co-existence, will allow all devices – regardless of vendor or purpose – to utilize the same frequency range and peacefully co-inhabit the same wire. Co-existence mechanisms must be deployed to solve problems between in-home and last-mile access and issues between different systems within the same home. To accomplish this, the industry must embrace two main ideas:

·        Frequency Division Multiple Access (FDMA) – FDMA appears to be the solution of choice for allowing co-existence between in-home networking systems and “last-mile” access systems. Effectively, this solution splits the frequency spectrum between isolated systems to eliminate contention. This is fairly effective, but minimizes overall throughput and potentially favors one system over another. Given these limitations, a coexistence mechanism that allows re-use of an unused neighboring system must be aggressively pursued.