Traditionally, video content transmission has been solely based on a baseband service, in which multimedia data (program content) was transported across a single channel, such as OTA, coax cable and/or satellite. Today, multimedia transmission is transitioning toward a broadband service, in which multimedia data is transported across multiple channels of signals and traffic types simultaneously.
Cloud storage has emerged from the desire to give the consumer more content. Content delivery methods have evolved over the years from one-way broadcasting to user-interactive, two-way methods such as VOD and digital video recorder (DVR). With VOD services, the content is stored on large servers located at remote sites, and the media are streamed to large numbers of independent and perhaps simultaneous (but asynchronous) users. Thus, as more and more devices — particularly handhelds and mobiles — consume multimedia content via streaming (as opposed to traditional “broadcast”) services, content and software capabilities are moving toward off-site remote storage systems.
A distributed system of servers deployed over the Internet at multiple data centers constitutes a content delivery network (CDN). Personal (consumer) multimedia storage systems are also moving toward network-based solutions such as network-attached storage (NAS) or network DVR (NDVR). Taken together, all of these storage approaches now constitute “the cloud.” With cloud services, users are afforded access to cloud computing and cloud storage resources, on-demand, over the network. In general, storage hosting companies and cloud storage service providers are not equivalent. Cloud storage is an online storage system where (multimedia) data is stored in virtualized pools of storage, connected by a network, as shown in Figure 1; users on a network terminal device access the data.
Figure 1. Cloud storage is realized as a virtualized storage pool.
Hosting companies operate large data centers, and users (individual or company) buy or lease storage capacity from them. The data center operators virtualize the resources in the background according to the requirements of the user and expose them as storage pools, which the users use to store files or data objects. The safety of the files depends upon the hosting websites.
Cloud for broadcast services
There are several areas in which broadcasters can take advantage of cloud storage technology. The first is using cloud storage for content serving and management. As interactive content access becomes realized through smart TVs and similar initiatives, on-demand services will require a large capacity (and quantity) of data servers that can be accessed by multiple transmission media and multiple device terminals. In order to support multiple device types from the same content data server, there is a need for users to manage content at one place that can be accessed by every (or any) device terminal owned.
Broadcasting services can also play a role as cloud hosting or cloud storage service providers. Current transmission media providers, such as cable, satellite, DSL, mobile or broadband, are taking a role as cloud hosting services by distributing content to multiple subscribed devices using VOD services and Internet streaming services; all of these form a virtualized online storage system to end-user terminal devices. Broadcasting services can also provide a personal content management tool for users to manage their viewing preference and improve viewing experiences across devices.
Another area of broadcast implementation is in providing a cloud DVR solution to users. Currently the DVR is based on personal storage, but the NDVR is gaining popularity, and affords users online data storage to record and access their favorite content. The cloud DVR service can add a service for users to store their personal videos as well as recorded content. This service allows users to build their own content library that can be accessed by any device they own, on-demand, at any location.
The cloud offers flexible content management to users. Cloud storage services offer users the opportunity to flexibly manage their content as they wish, to be delivered to any device in the most cost-effective way. The major cost factor of an on-demand service is the amount of storage resources and the number of simultaneous streams that can be supported, which are all dependent on media bandwidth. Because a large up-front investment is needed to establish such a service, the cloud solution offers flexible options that service providers can design to meet their objectives and budget:
- Users need only pay for the storage they actually use, without a full investment to build up a large storage system.
- Cloud service providers can choose between off-premises and on-premises cloud storage options, or a mixture of the two, depending on the cost-savings potential.
- Storage server maintenance tasks, such as backup, data replication and purchasing additional storage devices, are the responsibility of the cloud hosting companies.
- Cloud storage can be used for copying virtual machine images from the cloud to on-premise locations or to import a virtual machine image from an on-premise location to the cloud image library. Also, cloud storage can be used to move virtual machine images between user accounts or between data centers.
In addition, traditional multimedia delivery methods cause a user to tie one transmission medium to one device type. Cloud services, on the other hand, enable device architectures to become more decoupled from transmission schemes. This medium-device relationship is getting fuzzier over time, as users want to maintain a seamless viewing experience across their various media devices.
Challenges to broadcast services
Despite the many benefits afforded, cloud services also present challenges for broadcasting services, such as security and the reliability of the streaming performance.
Data distributed and stored at numerous locations increases the risk of unauthorized physical access to the data and also increases the number of networks through which the data travels. Instead of just a local area network (LAN) or storage area network (SAN), data stored in the cloud requires a wide area network (WAN). The risk of having data read during transmission can be solved by encryption technology. However, when more people have access to the data, the potential for error also increases, requiring highly secure content protection.
The basic idea of a cloud storage service is to “borrow” storage from a hosting company — but tying a content delivery business to a particular third party means the stored content is partially under a different entity’s control. Technically, with outsourced broadcasting services, multimedia quality is affected significantly by the network condition, including availability and reliability of bandwidth; streaming performance is thus a critical challenge for the multiplexing and smoothing technology used to buffer data.
Cloud services can be a cost-effective way to compete. Multimedia content consumption has been changing due to the growing number of mobile “smart” devices serving as a primary multimedia terminal for the masses. Cloud services provide a flexible, cost-effective alternative to the “traditional” mode of storing content and delivering broadcast services. The need for smart content management and delivery to multiple platforms can create huge costs for content resource management, but cloud storage has a big head start to optimizing this expense.
Challenges for cloud-based broadcasting services include handling multimedia data that are often time-critical, while providing a reliable and secure transmission. Obtaining stable, reliable and secure data transmission is a key factor for a solid cloud storage system for broadcasting.
—Aldo Cugnini is a consultant in the digital television industry and a partner in a mobile video services company.