DIPOL Weekly Review – TV and SAT TV, CCTV, WLAN

Will fibre optics help with weather monitoring?

A team of Nokia Bell Labs researchers has demonstrated how an optical fibre can be transformed into a functional sensor for monitoring both, the state of the communications infrastructure and environmental parameters – temperature and wind strength. A programmable FPGA chip was connected to a 524 km long fibre-optic cable stretching across Sweden, most of which is installed overhead.

The researchers monitored the signal for 70 hours to obtain data that they compared with that from weather stations distributed along the route. The analysis showed that a change in environmental conditions (wind, temperature) correlates with changes in the polarization of the optical signal recorded by the developed system. In addition, such a system, by recording the time of transmission of pulses through the optical fiber, is able to detect micro-changes in the length of the optical route resulting from the formation of slack or stresses on the fibers. This makes it possible to detect, among other things, dangerous tilts of the poles on which the cables are suspended.

The system developed by Nokia thus makes it possible to monitor selected weather phenomena to some extent, as well as to monitor the state of the telecommunications infrastructure in real time. Since fiber optic cables usually run along power routes, the security of both networks is monitored simultaneously.
Researchers are currently working on developing algorithms for real-time data analysis and autonomous decision-making, enabling the creation of early warning applications. In this way, the sensor can be used to increase safety and efficiency in managing energy infrastructure.

Signal brand LCD mounts for large TVs.

The choice of a bracket for hanging a TV set on the wall comes down to three main features: load capacity, size and mounting standard. The most important criterion is the load capacity of the wall bracket, since it directly affects the safety of the receiver and the people staying near it.

Each of the brackets presented below can be adjusted horizontally. However due to the construction and design solutions used this adjustment may not be permanent. The TV will tilt to the left or right when the setting is adjusted. This is the case with cheaper solutions intended for fixed TV positioning. For those who want to adjust the TV position, e.g. depending on whether it is watched from behind the table or from the sofa, we recommend the LPA49-466 E93170 bracket. The rigid structure, bushings and adjustable smoothness of movement will satisfy the most demanding customers.

Due to the fact that TVs with large sizes (55 inches and more) are becoming more popular every year, the following is a summary of the most popular mounts for large TVs.

Redirecting calls from the Villa Hikvision IP door/gate station directly to a smartphone.

1-subscriber Villa Hikvision IP video gate/door stations have the ability to be added directly to the Hikvision cloud and to redirect calls to a smartphone with the Hik-Connect application installed without the need for an additional internal monitor (otherwise a monitor is always required). To use this functionality connect the gate/door station to the Internet via wired or Wi-Fi link, create an account at www.hik-connect.com, install the Hik-Connect, and add the device to the account. Once the system is configured, pressing the call button on the door station will set up a connection on the smartphone with the app installed. After answering the call, it will be possible to have a two-way conversation and open the electric door strike or the gate.

In the diagram above, the door station has been connected to the router via a PoE switch that also provides power supply. The electric door strike is controlled by an additional 12 VDC power supply, via the first built-in relay in the door station. The second relay is connected to control the entrance gate. The user can view the image from the door station at any time via the application, even if no-one is calling and can trigger the relays if necessary.

Two HDMI to IP transmitters in one network.

By default, there cannot be more than one HDMI transmitter H3614 ( H3613, H3606) on one network. This is due to the fact that the manufacturer has uploaded the same network configuration on each transmitter. The user is not allowed to make any address changes to the HDMI devices. Therefore, if two transmitters are used, there is a conflict of IP addresses (resulting in incorrect network operation).

It is possible to perform such an installation but it requires the use of a managed switch and the creation of dedicated VLANs. In the example below, the user, by changing parameters on the switch, can create four scenarios for video display.

The whole configuration of such a network involves making a scenario-appropriate assignment of devices (specifically, the switch ports to which the devices are connected) to the appropriate virtual networks (VLANs). For example, to perform scenario #2, that is, the image on receiver #1 comes from transmitter #1 and the image on receiver #2 comes from transmitter #2.Assuming that:

• H3614 SENDER #1 is connected to port 1 of the switch,
• H3614 SENDER #2 is connected to port 2 of the switch,
• H3614 RECIVER #1 is connected to port 11 of the switch,
• H3614 RECIVER #2 is connected to port 12 of the switch,

configure the switch with VLAN options as follows:

• Port 1 - VID 11, PVID 11,
• Port 2 - VID 22, PVID 22,
• Port 11 - VID 11, PVID 11,
• Port 12 - VID 22, PVID 22.

10 Gbps in multimode fibre – OM2 fibre trap.

Transmission at 10 Gbps is now becoming the standard for implementing networks in office buildings, multi-family buildings and even homes.This speed is required not only in the backbone of the network, but also in the direct connection of end stations.

When deciding to use multimode fibers, remember that the ranges for 10 Gbps are limited. The most popular fiber standard MM om2 enables transmission at a speed of 10 Gbps over a maximum distance of 82 m, i.e. less than copper twisted pair category 6A certified for that speed (100 m according to the 10GBASE-T standard). This is can be really tricky to network designers or contractors who do not pay attention to the fiber standard in the cable used.

Higher multimode fiber standards, i.e. OM3 and OM4, allow 10 Gbit/s transmission over distances of respectively: 300 m and 500 m. The choice is much safer in this matter. The affordable OM3 is a good choice also from the perspective of local network development, because it offers connections with speeds of 40 Gbitps and 100 Gbitps at a distance of 100 m.

Video intercom system for an apartment block. A diagram of the Hikvision IP video intercom system for a 10-story (40 apartments) apartment block is shown below. Two identical sets of gate/door stations are installed at the gate and entrance to the block which include: main module with a camera (DS-KD8003-IME1/EU G73652), Mifare tag reader (DS-KD-M G73662), keyboard to control the first relay in the station (opening ) the wicket gate and calling individual tenants (DS-KD-KP G73668), and a display module indicating the door station status and allowing to choose s subscriber from the list...>>>more