Introduction

Historically, the radio spectrum has been managed in a rather rigid fashion where systems have been constrained to very specific bands in order to avoid interference and maintain the spectrum's viability. This regime is extremely inefficient, because at any one time many systems are not being used thereby leaving their associated spectrum also unused. Alternative spectrum management, where systems not designated for a particular band may nevertheless use it if it is available, would greatly increase spectrumusage efficiency and capacity.

Communications traffic has also historically been managed in a somewhat inefficient manner, whereby traffic load has usually only been carried on a specific band as directed by the “owner” of the user/device carrying the traffic. Improved traffic-load management techniques, where the traffic can be shared among bands and systems, would also increase efficiency or capacity. Although the end-user may sometimes have a limited choice of which band to receive traffic on (e.g. via a Wi-Fi interface using an ISM/UNII band, or via a 3G mobile communications interface using a UMTS band), centralized control of that choice, in a timely fashion, can far better manage efficiency and capacity than the end-user operating alone.

Such opportunistic load and spectrum management between bands/systems is being made feasible by operators having an increasingly wide range of spectrum bands at their disposal, of very different frequencies and physical characteristics. Operators may typically operate a range of different systems on this range of spectrum bands.