Architecture & Engineering (A&E) Basic introduction to IP surveillance Introduction IP, what is that? Sender/ Source host The abbreviation IP stands for Internet Protocol What is an Internet Protocol then? The Internet Protocol is responsible for addressing hosts and routing data packets from a source host (the sender) to a destination host (the recipient) across one or more IP networks. Data on the IP network is divided into packets that are send in arbitrary order via the best available route in the network and then reassembled in the correct order at the destination. Each packet contains:
An amount of the data information. The senders IP-address. The intended receivers IP-address. Information about the number of packets the data message is divided into. Packet 1 Router A Packet 3 Packet 5 Router B Packet 4 Packet 2 Recipient/ Destination host 2 Introduction
You may have heard the term TCP/IP? TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language of the Internet. The TCP (Transmission Control Protocol) part running on the transport layer, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP protocol that reassembles the packets into the original message. The IP (Internet Protocol) part running on the internet layer, handles the address part of each packet so that it gets to the right destination. Each gateway computer on the network checks this address to see where to forward the message. Even though some packets from the same message are routed differently than others, they'll be reassembled at the destination. The most dominant protocol of the Internet today is called IPv4 (Internet Protocol version 4). This protocol uses 32 bit for defining a IP-address, which is able to support approximately 4 billions addresses. As the need for more IP-addresses is increasing, a successor called IPv6 (Internet Protocol version 6) is introduced and in growing deployment worldwide. This protocol uses 128 bit, supporting approximately 3.4 x 1038 addresses, which provides considerable high flexibility in allocating addresses and routing traffic. 3 Network What is a computer network? Basically a computer network is a collection of computers and devices interconnected by communications channels that facilitate communication among users and allows users to share resources. Networks can be divided into various classifications.
Most used are: LAN Local Area Network, connects computers and devices in a limited geographical area, e.g. office buildings. The LAN is often based on Ethernet technology. WAN Wide Area Network, covers a large geographical area such as a city, county, or even intercontinental distances, using a communication channel that combines many types of media, e.g. telephone lines and cables. 4 Network Networks can be either cabled or wireless Notes concerning cabled network: Faster connections between computers up to 1.000 Mbps (megabit per second). More reliable network connection. Cannot be interrupted, broken or disturbed so easily. A cabled network is more safe.
Notes concerning wireless network: Flexible usages of portable equipment. Cables are not needed in order to go onto the internet, provided that the Wireless Access Point can be reached and the wireless signal can be amplified. Cheap to install, requires minimum amount of cable installation. Wireless Router is normally configured with some kind of security. Currently the bandwidth standard is 54 Mbps. Wireless network is easier to interrupt and disturb. 5 Network Ethernet technology Ethernet is a family of frame-based computer networking technologies for Local Area Networks (LANs) and Wide Area Networks (WANs). Ethernet is a standard. Two Ethernet units can be connected via an Ethernet switch. Ethernet exists today in primarily two versions, either 10/100 Mbit and 10/100/1000 Mbit. Ethernet, calculation example 10 Mbit = 1.280 KB/s, i.e. it is capable of transmitting 1.280 KB data per second. 100 Mbit = 12.800 KB/s, i.e. it is capable of transmitting 12.800 KB data per second. Bits and Bytes
Bit = One binary digit, i.e. 1 or 0. Byte = Eight bits, for example: 00000001. One byte (8 bits) gives 256 values, from 0 to 255: 0 = 00000000, 255 = 11111111. Two bytes (16 bits) gives 65.536 values, from 0 to 65.535: 0 = 0000000000000000, 65.535 = 1111111111111111. 00000000 00000001 00000010 00000011 00000100 00000101 . . . 01111110 01111111 11111111 6
IP-address What is an IP-address? An IP-address is the computers "address" or telephone number. Two Ethernet units connected to the same network cannot have the same IP-address without a conflict. IP-addresses consists of 4 groups of octets. Each octet is 8 binary digits. The decimal values in an IP-address, for example 192.168.90.1 is in fact represented by binary values as shown in the example below: octet 1 192 octet 2 . 168 octet 3 . 90
octet 4 . 1 11000000.10101000.01011010.00000001 7 Subnet What is a subnet? Subnetting is a subdivision of an IP network, i.e. a smaller network within a larger network. Using subnets on an IP network can be done for a variety of reasons, for example organizational, for preservation of address space, and security. The most common reason is to control network traffic, for example larger organizations can use subnets to isolate heavy data traffic running internally in one department from the rest of the company and by this reduce the amount of traffic and increase network performance for the rest of the company, etc. 8 Storage Why is storage so vital to video recordings?
In the digital domain storage is important because video recording in general means a large amount of video data we have to keep for shorter or longer periods of time. The storage mediatypically a hard diskis what film and tape were to analog cameras and analog video recording equipment. As with analog cameras and analog video recording, the longer the film or tape is, the more pictures it can contain or save. In the digital domain it means that the larger hard disk in MB (or GB), the more video data recordings can be stored on it. 9 Storage How can users access the same storage source? Client This is possible by the client-server model that is characterized by a central server and an arbitrary number of clients. Client Client
Client-server is generally used for ressource management operations, where several different users (clients) want to share a common ressource. The server is responsible for managing this ressource. Query Reply Server (storage) 10 Storage Storage system types, some examples:
DAS Direct Attached Storage. Digital storage device directly connected to a server. NAS Network Attached Storage. File-level computer data storage connected to LAN, using TCP/IP for communication. SAN Storage Area Network. Network hard disk, that often has better performance than the PCs drive C. DASD Direct Access Storage Device. Any kind of storage, i.e. tape, hard disk, memory stick, etc. SATA Serial Advanced Technology Attachment. Computer bus interface for connecting host bus adapters to e.g. hard disk drives. SCSI Small Computer Systems Interface. Set of standards for physically connecting and transferring data between computers and peripheral devices. iSCSI internet Small Computer Systems Interface. IP-based storage networking standard for linking data storage facilities. SAS Serial Attached SCSI. Computer bus used to move data to and from computer storage devices such as hard disk drives and tape drives. 11 IP Network Camera What is an IP camera? An IP camera can be seen as a camera with a built-in mini computer and web server sending image information as digital data to the network it is connected to. An IP camera often has the same or better specifications than a
corresponding analog camera type. Some IP cameras have built-in e-mail client, alarm handling, input/ output function, motion detection, etc. An IP camera does not necessarily need separate power supply as it is powered through the network referred to as Power over Ethernet (PoE). 12 IP Camera Image Sensor What is a camera image sensor? An IP camera is equipped with an image sensor that is the eye, or more specific the retina" of the camera. The image sensor converts what is projected to it from an analog image to digital data values. The image sensor comes in different sizes. The larger the physical size of the CCD (image sensor) is, the more detailed picture. Image sensor and camera lens must fit together to give optimal picture/image quality, for example: 13 Camera Image Resolution What is a pixel in digital imaging?
A pixel is a single point in an image and the smallest screen element that can be controlled: One pixel Each pixel has its own address that corresponds to its coordinates. On color monitors a pixel can typically represent the following three colors: red, green and blue. How is image resolution defined? Image resolution describes the details of an image. Higher resolution means more image details: Pixel resolution is often defined as pixel counts of the width and the height of the image, for example 2048 1536. Pixel resolution can also be defined as the total number of pixels in the image, for example 3.1 megapixels, which is equivalent to the example 2048 1536 mentioned above. 14 Image Format and Compression What is video coding? Video coding basically enables compression of digital video. IP video surveillance systems normally operates with three video coding formats:
JPEG and MJPEG (Motion JPEG) are methods for compression of digital images. The degree of compression can be adjusted to find a reasonable condition between storage size and image quality. For MJPEG, each video frame of a video sequence is separately compressed as a JPEG image. MPEG4 is a standard used for data compression and distribution of digital images. The compression reduces the amount of data without reducing the image quality. H.264 is a standard used for data compression of digital images. It contains an enhanced compression method that can reduce digital video file by more than 80% against the MJPEG standard while maintaining the same visual quality. Compared to MPEG4 the reduction is approx. 40-50%. 15 IP Video vs Analog CCTV What is the main difference between IP video and analog video systems? IP cameras can be connected directly to the network via an Ethernet cable. Connecting existing or new Closed-Circuit-TeleVision (CCTV) cameras to the IP network can only be done via an IP video encoder (also called video server).
The video encoder digitizes analog video signals and sends digital images directly over an IP network, such as a LAN, intranet or Internet. It essentially turns an analog video system into a network video system. The analog CCTV camera is connected to the analog input on video encoder via its coaxial cable. The output from the video encoder is digital and provided via an Ethernet socket that can be connected directly to the network. IP video encoders is available in different versions handling from one single analog camera to multiple cameras. 16 IP Video vs Analog CCTV In general, IP video technology is superior to analog CCTV systems because... Lower cabling costs Category 5 cabling costs a fraction of the coaxial cables used in CCTV and the cable runs are typically much shorter. Cat 5 cable is a twisted pair high signal integrity cable type, normally used in structured cabling for computer networks such as Ethernet Remote monitoring CCTV cameras do not support remote monitoring whereas IP camera allows direct connection to the Internet making them accessible (with permission) from any PC or with newer cameras a cell phone. Scalability IP Video Systems can be scaled simply by adding network cameras in increments of one, and so can industry standard storage. Remote data storage
Video can be recorded and stored remotely from cameras, giving better data security. Better security The automated and advanced features of IP versus CCTV cameras (such as email notification upon detected motion) provides automated, real-time event notification. This allows better analysis and timely response to events and then better chance to react. 17 Open Platform IP Video Why choose open platform IP video solution? Freedom of choice by selecting the components you want. Easy to connect and integrate into your existing network and security systems. Cost-effective by reducing total cost of ownership.
Future-proof solution that keeps up with the everquickening speed of innovation in the video surveillance industry. Possibility to extend your IP video system to improve a whole range of business processes, for example by integrating third party systems. ss e e i i t t i i iill b b i i ssss o
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