Wednesday, April 30, 2014

DTE & DCE / DB25 & DB9 Port

DTE & DCE / DB25 & DB9 Port

Let's talk about DCE (Data Communications Equipment) and DTE (Data Terminal Equipment) devices. The difference between DCE and DTE is largely in the Plug and the direction if each pin (input or output). Your desktop PC is termed as a DTE device.
DCE devices use a 25-pin female connector while a DTE device uses a 25 pin male connector. Also, complimentary signals lines like transmit and receive are "swapped" between the two types. Thus, a straight-through cable can be used to connect a DCE device to a DTE device.
25 pin Male pinout25 pin Female pinout
Pin 1 - Shield GroundPin 1 - Shield Ground
Pin 2 - Transmitted Data (TD) outputPin 2 - Transmitted Data (TD) input
Pin 3 - Receive Data (RD) inputPin 3 - Receive Data (RD) output
Pin 4 - Request To Send (RTS) outputPin 4 - Request To Send (RTS) input
Pin 5 - Clear To Send (CTS) inputPin 5 - Clear To Send (CTS) output
Pin 6 - Data Set Ready (DSR) inputPin 6 - Data Set Ready (DSR) output
Pin 7 - Signal GroundPin 7 - Signal Ground
Pin 8 - Carrier Detect (CD) inputPin 8 - Carrier Detect (CD) output
Pin 20 - Data Terminal Ready (DTR) outputPin 20 - Data Terminal Ready (DTR) input
Pin 22 - Ring Indicator (RI) inputPin 22 - Ring Indicator (RI) output
You can effectively convert DCE/DTE devices by using a NULL Modem cable. The null modem cable swaps the complimentary signals and allows a DCE device to act like a DTE and vice-versa.
The following chart depicts the cabling of the DB9 connector found on an IBM-PC type computer.
9 pin Male pinout
Pin 1 - Carrier Detect (CD) input
Pin 2 - Receive Data (RD) input
Pin 3 - Transmitted Data (TD) output
Pin 4 - Data Terminal Ready (DTR) output
Pin 5 - Signal Ground
Pin 6 - Data Set Ready (DSR) input
Pin 7 - Request To Send (RTS) output
Pin 8 - Clear To Send (CTS) input
Pin 9 - Ring Indicator (RI) input

What are the actual speeds of GPRS, EDGE, UMTS, HSPA, etc in Video Surveillance?

What are the actual speeds of GPRS, EDGE, UMTS, HSPA, etc in Video Surveillance?

Theoretical maximum speeds of 4G LTE reach 100Mbps so you’re Video is Real time and no buffering... However, actual performance of mobile data is much lower, considering signal strength, frequencies used, congestion, etc.

Here are the real-life speed ranges of the various mobile wireless standards commonly used in the India today:-

GSM (Global System for Mobile Communications) 2G -- 9Kbps
GPRS (General packet radio services) 2.5G -- 20Kbps to 100kbps
EDGE (Enhanced Data rates for GSM Evolution) 2.75G -- 100Kbps to 175Kbps
UMTS (Universal Mobile Telecommunications System) 3G -- 175Kbps to 1Mbps
HSPA (High Speed Packet Access / software upgrade to UMTS, theoretical 42Mbps) 3.5G -- 600Kbps to 10Mbps, averages 1-3Mbps
WiMAX/LTE "4G" (theoretical 100Mbps) -- 3Mbps to 10Mbps average, 20Mbps+ peak download speeds.
5G -- 250Mbps to 500Mbps in South Korea & Japan on 2014

So select your Mode for traveling path of Video Surveillance data.

3G/4G Video Surveillance Advantages
  • 3G/4G Performance = faster upload speeds = higher frame rates & better resolution
  • Connect multiple Wired and Wireless IP cameras to 1 LAN-Cell
  • Bandwidth Management features to prioritize video traffic
  • Port Mapping, Redirection & DMZ features to minimize changes to camera configuration
  • Dynamic DNS support to access cameras by name or IP address
  • Deploy a single platform on CDMA & GSM networks worldwide

Tuesday, April 1, 2014

Router Compatibility for Internet Enabled Wireless CCTV Systems

The modern replacement for old analogue CCTV cameras is the wireless internet CCTV, also known as IP CCTV. The wireless CCTV system that is internet enabled has a great advantage over old system. You can see your property from anywhere in the world. You can see live images and video of your business property or your house, from wherever you are, just with the help of internet.
The technology has come in the market, but not many people know how to best use to. In order to get the best out of your wireless internet CCTV system, we must also look at the requirements and features that a router would need in order to be used successfully with the wireless system. There are a lot of things that goes into deciding your router for the wireless internet CCTV.

Broadband Type and Router Compatibility

You can have a broadband service that can come through either a phone line or a satellite CCTV box. In case the broadband service is through a phone line, you will require an ADSL modem/router also known as the DSL modem/router. Alternatively, if your broadband comes from your cable supplier, you would then require a cable router. This is another box that plugs in to your cable box.
The router part of your DSL modem/router or the cable router is basically the same. Manufacturers just make the DSL or cable version of the router that has the same features.
Router Features for Wireless CCTV System
  • The router must be set up so that the port number, a special code, is allocated to the camera. When you type the IP address and the port number in the internet browser from any system, the router sees the port number and passes the message to the camera. Without this facility, it will not be possible to view your property through internet.
  • With broadband suppliers changing your IP address at will, DDNS i.e. dynamic DNS support comes in. It helps you to use a third-party service to link a domain name you your IP address. The router’s DDNS feature makes sure that the router will tell the DDNS provider about your current IP address. Thus, even if your IP address changes, you can contact your camera with the domain name of the DDNS.
  • Having your router remain connected is very important. This is important especially when you go out on a vacation. You don’t want to find that you cannot connect to your camera because your router disconnected due to power failure. In case of power cut, the DSL line or cable may drop for some time. Not many home routers are able to handle this, but with technology, new routers are able to reconnect by themselves after power cut. The router is able to sort itself out once the power is back and provides you hassle free access to your camera from anywhere in the world.
Thus, a router is an important device that enables you to monitor the security of your home and business’s wireless cctv systems from anywhere in the world.

Choosing Routers for Wireless Internet CCTV

Wireless Internet CCTV, also known as IP CCTV, is the modern replacement for old analogue CCTV cameras, and has the great advantage that you can see your property, live, from wherever you happen to be, using the internet. Now that the technology has become popular in homes and businesses, people need to know how to get the best out of it. In this article, I want to look at the minimum set of features that a router needs in order to be used successfully with wireless CCTV.
First, a quick note about types of broadband and router compatibility. Your broadband service is likely to come through your phone line or perhaps via a satellite CCTV box. If it’s through a phone line, you will need an ADSL modem/router, sometimes called a DSL modem/router. The modem part of the box is what talks to the phone line. On the other hand, if you have broadband from your cable supplier, you need a cable router. This is not the cable box itself, but another box that plugs into your cable box. The router part of a cable router or a DSL modem/router is usually the same, with many manufacturers making cable and DSL versions of what is essentially a router with the same features. Now, let’s take a look at the features you will need to get the most out of your wireless internet CCTV system:
  • Virtual Server/Port Forwarding. This just means having the ability to set up the router so that a special code known as a port number is allocated to the camera. When you open an internet browser window and type in the URL or address of the camera, you add this special port number onto the end of the camera’s address, (e.g. for port 8765, you would type “http://:8765″) and when the router sees the port number it knows the message is to be passed to the camera. Without this facility, you would not be able to see your property over the internet.
  • DDNS Support. It stands for Dynamic DNS and is used where the address of your home or business on the broadband system, known as the IP address, is changed at will by the broadband supplier. Most DSL broadband services have changing IP addresses, also known as dynamic IP addresses. Say you have an IP address of (they tend to look like this) today, with dynamic IP addressing it could be something different tomorrow. This means you would never know what address to use to access your camera over the internet, and that is where DDNS support comes in. Basically, you use a third party service to link a domain name to an IP address. This service is provided by a separate DDNS provider and can be free, e.g. The router’s DDNS feature means that the router makes sure it always tells the DDNS provider what your current broadband IP address is. Therefore, even if the IP address changes, you can always contact your camera by using the same dyndns address, e.g. “″.
  • Keep alive or auto-reconnect feature. This feature is all about making sure the router stays connected. You may have a power cut, or the DSL line/ cable connection may drop for a few moments. In these scenarios, you want the router to sort itself out. Earlier models of home router did not handle this well, and even today some can still be bought that don’t reconnect after a power cut or especially a broadband fault. The last thing you want is to go on holiday and then find you cannot log into your camera because a power cut several days ago left the router disconnected, so this is important.
  • Encryption. Most routers these days offer some sort of encryption, usually known as WEP or WPA. WPA is stronger and preferable. Encryption is simply encoding the messages on your wireless network so that they cannot be intercepted easily. Make sure you get a router that offers at least one type of encryption that your wireless internet CCTV cameras offer. For example, it is no good getting a router which only does WPA encryption if your cameras can only do WEP.
As always, if what you have read here leaves you dizzy and you just want an internet CCTV system to monitor your home or business without all this technical complication, my advice is to get a fully-configured wireless CCTV camera pack from a specialist supplier.