This specification defines the basic Linear TV service operation after the initialization@ configuration@ service provider discovery@ and services discovery documented in ATIS-0800017@ Network Attachment and Initialization of Devices and Client Discovery of IPTV Services [5] and ATIS-0800009@ Remote Management of Devices in the Consumer Domain for IPTV Services [3]. Note that those specifications may enable an IPTV Terminal Function (ITF) to access additional IPTV services beyond the basic Linear TV service described in this specification. This specification defines the interfaces required between the Service Provider Domain to the Consumer Domain@ as well as the essential Network Stratum interfaces. The Service Provider can provide additional processing of the video stream -- e.g.@ insertion of local content channels@ advertising@ etc. -- but such mechanisms are beyond the scope of this specification. Section 4 identifies the specific interfaces to be specified in this document in relation to the IPTV High Level Architecture components and interfaces. The scope of this specification ends with the delivery of the content to the ITF. Further distribution beyond the ITF@ user interface controls for presentation on a television set@ etc.@ are beyond the scope of this specification. The Service Provider can replicate the content stream to multiple Delivery Networks@ and the Delivery Networks can replicate the content stream for multiple home networks. This specification covers a client-server architecture (i.e.@ not peer-to-peer) with delivery via IP multicast (i.e.@ not unicast) techniques. This specification describes a basic acquisition mechanism for Linear TV content channels with options for various network resource allocation mechanisms. This specification can be used for low bandwidth and/or wireless infrastructures@ but it is not optimized or explicitly addressed for those purposes. Content can be received by the service provider via satellite or other means@ but hybrid delivery (i.e.@ via mechanisms other than an IP network infrastructure) of content to the consumer domain is beyond the scope of this specification. The content delivered via the Linear TV service may be either secured or unsecured. Where content security is required to ensure confidentiality of the content and constrain its further distribution@ appropriate Digital Rights Management mechanisms are used. These mechanisms are beyond the scope of this specification. This specification assumes the ITF is authorized to access one or more service packages. Mechanisms to restrict or modify the set of available authorized service packages are beyond the scope of this specification. Purpose The purpose of this document is to describe the use of the components identified in ATIS-0800007@ IPTV High Level Architecture [2]@ for delivery of an IPTV service with a consumer experience similar to that of a traditional television service.