available. Since the cost of provisioning a given QOS will also depend on current traffic conditions, it is desirable that pricing be traffic dependent. Many connections will involve two or more network service providers, each provisioning identical rate parameters, but possibly contributing quite different impairments such as loss and delay to the end-to-end QOS (based on their technology, local traffic conditions, etc.). Those network service providers should derive revenue that is related to their contribution to end-to-end QOS, since otherwise they will all have an incentive to fully consume the end-to-end impairment objectives.
Thus, we conclude that the pricing to the user and division of revenue should be established based on the rate parameters, the contributions to the impairments of the individual network service providers, and local traffic conditions. This requires a complex negotiation between the application and a set of network service providers to establish an end-to-end QOS that achieves an appropriate trade-off between price and QOS, and a partitioning of that QOS among the network service providers. One approach is a broker that mediates among the application and all potential network service providers. A desirable feature of a brokerage system from the user perspective is that all available network service providers could be considered, choosing the set of providers that is most economic based on their current traffic conditions and pricing strategies.
Looking at the NII from a user perspective, we can identify some key challenges for the future:
The greatest challenge in the NII is to allow for and encourage a variety of technologies, applications, network service providers, and applications service providers to coexist in a dynamic environment, while satisfying the user's desire for interoperability, openness to new applications, and acceptable levels of performance. This will be possible only with initial planning and coordination and ongoing cooperation among all parties involved.