Читать книгу Dynamic Spectrum Access Decisions - George F. Elmasry - Страница 77

The literature shows how different wireless communications systems study DSA from different angles. One can find many references on dynamic spectrum management for 5G cellular systems. The next chapter covers 5G dynamics spectrum management as one example of DSA systems. There are also cognitive radio references that look at DSA from the angle of opportunistic spectrum use and military‐focused DSA references that are built on the military concepts of operations covered in Part 3 of this book. The previous chapters explained many DSA concepts from the cognitive MANET perspective. This chapter looks at DSA without having any specific system or application in mind. This chapter is a case study where the case is generic. DSA is presented as a collection of cloud services that can be accessed on any hierarchal entity¹ of a hierarchy of heterogeneous networks and DSA services are made available wherever and whenever they are needed.² As the reader moves to the next chapter, 5G dynamic spectrum management may be viewed as a specific case study that can be derived from the generic representation of DSA as a set of cloud services presented in this chapter.

The National Institute of Standards and Technology (NIST) defines cloud computing as “a model for enabling ubiquitous, convenient, on‐demand network access to a shared pool of configurable computing resources – e.g., networks, servers, storage, applications, and services – that can be rapidly provisioned and released with minimal management effort or service provider interaction”. The goal of this chapter is to present a case for DSA to be designed as a collection of cloud services that are ubiquitous, convenient, and on‐demand for a shared pool of spectrum resources or frequency bands. Spectrum resources can be provisioned and released at different speeds depending on the hierarchy of heterogeneous networks with minimal management effort from a human in the loop. In addition to offering DSA services from provisioned spectrum resources, DSA cloud services can tap into opportunistic spectrum resources as well.

When interference is detected³ by any entity, a service request for a new frequency band to operate on can be triggered. The client for DSA cloud services here is not an actual person. The client is a network entity that is suffering from interference. The service is to re‐provision spectrum resources to accommodate all networks and nodes needed for seamless wireless communications.

NIST provides different service models for cloud computing that include infrastructure as a service (IaaS). DSA services can follow the IaaS model.