## 4 Video Surveillance System Architecture  
The USVS system consists of SVS, a Smart-City Video Analyzer (SCVA), and a Video Manager (VM) in the SOUL middleware platform tier, as shown in Figure 2. The VM manages the SVS and the SCVA. The Camera Manager (CM) manages and monitors the status of cameras connected to the smart city. The Storage Manager (SM) monitors the status of the storage in the SCVA. The Analyzer Manager (AM) manages the frame rates, codec, and resolution of video at the user's request and monitors the status of the MapReduce Analyzer (MA). The Protocol Manager (PM) manages video streaming protocols. The real time messaging protocol and real time streaming protocol were supported.  
The SCVA had components of the Streaming Receiver (SR), the storage, and the MA. The SR receives video streams from the SVS to collect video data over converged networks from scattered video cameras. HDFS was used by the SR to store large video data. In the next section, the MA is described in detail.  
Many video cameras are required to efficiently operate a smart city in smart cities. So, the USVS system was designed to efficiently manage big video data, and its scalable video streaming component enables smooth management of big video data traffic from numerous network video cameras.  
Figure 1: UTOPIA Smart Video Surveillance (USVS).  
Figure 2: The architecture of USVS.  
Figure 3 shows that it uses a novel mechanism to control the admissions of clients, extracts the bit stream, and allocates appropriate channels for context-aware and network-adaptive video streaming. Self-learning using scalable video coding techniques saves the system and network resources [40].  
The working mechanism of the SVS is explained now. The data from each networked video camera in the smart city are encoded by a Media Encoder (ME). The SVS checks the change instructions from the Quantization Parameter (QP) changer when encoding the data. The QP changer encodes the obtained data with various QP values determined using the information of the Network Channel Bandwidth Monitor (NCBM). The NCBM plays the role of a network analyzer. It uses the available bandwidth of the Streaming Receiver (SR), the strength of radio wave signals, and a feedback signal to analyze the network bandwidth in real-time. When initialized, the SVS sends a message to the SR of the SCVA and the Feedback Control (FC) of the SR respond with available bandwidth. The SR thinks that the network channel is in good condition, if the signal is strong. Conversely, the SR thinks that the network channel is in poor condition, if the signal is weak. The FC of the SR helps the NCBM evaluate the condition of the network channel. The SR responds after receiving data. If the channel condition changes very often, the FC sends the information at a minimum until the channels stabilize. In order to evaluate the network channel, this information is used again. The FC sends the information of the current bandwidth of SR to the SVS. The SVS determines the QP value using this information. The NCBM continuously monitors the condition of the network channel. The NCBM evaluates the available bandwidth and communicates with the QP changer to control the encoding rate according to a predetermined QP value. After it, the QP changer adjusts the encoding level. For network adaptive live streaming, live video data are encoded with the determined QP value by the ME. After encoding, the encoded video data are transmitted to the Bit-stream Extractor (BE) and the Stream Manager (STM), which packetize data appropriately. Finally, the data packets are separated for adaptation to various network conditions.  
Figure 3: The operation of the USVS.