Page 785 - Cloud computing: From paradigm to operation

Video processing and storage 4

The traditional VS service is a telecommunication service focusing on video (and audio) application
technology, which is used to remotely capture multimedia (such as audio, video, image and various alarm
signals) and present them to end users in a friendly manner (including accessibility aspects). The traditional
VS system mainly includes six functional entities, which are the centre management unit (CMU), the service
control unit (SCU), the media distribution unit (MDU), the media storage unit (MSU), the premises unit (PU)
and the customer unit (CU). The function description of each functional entity is defined in [ITU-T H.626].
A visual surveillance cloud storage can provide a shared pool of configurable storage resources and related
data storage functions to the VS applications. In a cloud storage system, the storage resources can be
dynamically assigned and reassigned according to the users' demands. The cloud storage part mainly includes
three functional entities, which are the cloud storage management unit (CSMU), the cloud storage data unit
(CSDU) and the cloud storage access unit (CSAU).
– CSMU is used to provide the management services for the cloud storage system in the VS system.
– CSDU is the data node in a cloud storage system. A number of CSDUs are organized in a distributed
way as a storage resource pool by using virtualization technology and the virtualized storage
resource can be dynamically provided to the users on demand. The CSDUs are used to store the
massive multimodal data produced by the VS system.
– CSAU is the key unit for implementing communication between the CSDU and the media data
related units defined in the traditional VS system [ITU-T H.626]. The main functions of the CSAU
include: receiving and responding to the control information of the CSMU, receiving and responding
to the control information of the SCU, receiving the media data from MDU or PU, sending the media
data to the MDU or other related visual surveillance entities, writing the media data into the CSDU
cluster and reading the media data from the CSDU cluster.

7.2 Functional entities

7.2.1 Cloud storage management unit
The cloud storage management unit (CSMU) is used to provide the management services for the cloud
storage system and respond to service requests of the VS system. The main functions of the CSMU include
storage resource management, data management, user management, service management, log
management and security control. The CSMU is used to achieve collaboration among the different storage
devices and guarantee better access performance of the multimodal surveillance data.
7.2.2 Cloud storage data unit

The cloud storage data unit (CSDU) is the data node in a cloud storage system which is used to store the
massive multimodal data produced by the VS system. A typical visual surveillance cloud storage system has
a number of CSDUs, which are organized in a distributed way as a storage resource pool by using virtualization
technology. The CSDU can be dynamically extended according to the user's demand and the virtualized
storage resource can be dynamically provided to the users on demand. The CSDU can receive media data
from the CSAU and write the data onto its local storage device. In addition, the CSDU can read and transmit
the stored data to the CSAU according to the data reading requests.

7.2.3 Cloud storage access unit
The cloud storage access unit (CSAU) is the key unit for implementing communication between the CSDU and
the media data related units defined in the VS system [ITU-T H.626]. As shown in Figure 7-2, the functions of
the CSAU are divided into three categories, which are the service control function, the media control function
and the configuration management function.

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