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

The era of unmanned ships is coming!

In the era of drones and first autonomous vehicles, there are also attempts to develop unmanned marine cargo vessels. The new solution is being developed by a team of Blue Ocean, with members coming from the Norwegian office of Rolls-Royce Marine and VTT Technical Research Center of Finland. Tests are carried out on the Baltic Sea due to its location and relatively "small size".

The very concept of unmanned vessels appeared nearly 10 years ago, but the advanced work on the prototype began only last year. To this day, Rolls-Royce engineers have created so-called virtual captain's bridge, which displays detailed meteorological data, the exact coordinates of vessels in the vicinity and an interactive map that allows avoid obstacles with minimal fuel consumption. In addition, the bridge provides images from systems of traditional and thermal imaging cameras that allow navigation in zero visibility, such as during fog, dense snowfall or rain.

Visualization of the remote captain's bridge
(source: vtt.fi)

In the future, virtual bridges designed to control unmanned ships will be remote command centers. From the other end of the world, the captain will have a clear view of everything that is happening on the ship and around it, using internal and external cameras, sensors deployed in different points of the ship, information from motors and other equipment. All the data will be automatically monitored in order to detect failures in the early stages, as well as to prevent other adverse events.

The emergence of unmanned bulk carriers and container ships will reduce the risk of hijacking and demanding ransoms for the crew members. The obvious aspect is also financial benefits from the reduction of human resources. The vessel will be operated by one person, who may even supervise several such ships. The captain will not be set off on a multi-day trip, but can work in the comfort of their residence. Currently, the average cost of the crew is $ 3300 per day, which represents about 44% of all operating costs. The reduction of the number of the crew members will automatically reduce the operating costs. The total elimination of the crew will allow to convert cabins, canteens and all rooms intended for people into cargo space.

There is a long way from a concept to implementation, however, with hundreds of hours of testing. And the complete elimination of the human crew is currently not possible due to law restrictions that exactly specify the minimum crew size for various types of vessels.

Started in the eighteenth century, industrial revolution still continues, machines and robots spread into every corner of life. Direct M2M communication eliminates the need for supervising thousands of parameters by the man. Given the financial benefits of investors, the introduction of unmanned vessels does not seem to be a distant future.

Keep the standards ...

The use of fiber optics in a system is often covered by specific regulations. They frequently apply to to the type of cables, fibers and connectors. In the case of fibers, they are made according to international standards.

Currently, the most popular types of single-mode fibers in FTTx systems are G.652D and G.657A. These same types of fibers are used in pigtails. It is worth noting that if the regulations require the use of a certain standard, say G.657A, the same fiber should be used in the pigtails spliced to the fibers. Otherwise, the installation would not comply with the specification.

How to choose analog RF modulators for shared antenna systems?

Baseband audio-video signals can be included into an RF distribution system by the use of a modulator. The signal source can be a PC, DVD / Blu-ray player, and most often a media player with previously created content.

Looking for an appropriate RF modulator, the user should pay attention to the maximum level of the output signal. With higher levels, there is a chance to inject the signal into the system without an additional amplifier, even when it is distributed to a grater number of outlets. Modulators with maximum output level of 75-80 dBuV are only suitable for individual antenna systems (e.g. to send the signal from a DVD player to another room). The following table shows examples of high class analog modulators from TERRA.

The MT-29 R871729 and MT-32 R871734 modulators feature high maximum output levels that are sufficient for distribution of the output signals to 30-40 outlets without using an additional amplifier. The MT-32 model is recommended for systems distributing multiple channels - VSB modulation allows for operation on a channel adjacent to another active channel.

The MT-31 R871736 modulator can also operate on an adjacent channel, however it is recommended for small networks or has to cooperate with a suitable amplifier.

The mt420 R82515 twin modulator is ideal for use in small headends. The modulators can be connected in series and located on one DIN rail. The DIN rail can carry up to 8 such modulators, distributing up to 16 channels.

What to do when there is no place for the DVR?

In situations where it is difficult to find a suitable place for the CCTV DVR/NVR, it can be mounted on a wall in vertical position. This mounting option is provided by small cabinet Pulsar AWO 529 M5713. The cabinet is made of steel sheet with a thickness of 1 mm and is protected against corrosion. The lockable cabinet protects the DVR/NVR against unauthorized access or theft.

View of the inside of the Pulsar AWO 529 M5713 cabinet
(with Ultimax 1208 M72208 DVR - not included)

After opening, the front door is held in a horizontal position, so that the user is provided with easy access to the buttons on the front panel of the protected device. The cabinet is equipped with a special adjustable bracket that allows for the installation of a DVR/NVR with various dimensions. The cabinet is suitable for M72204, M72208, M72216, M72404, M72208, M72216 CCTV DVRs and K2104, K2204 IP NVRs.

Hybrid video surveillance system for a housing development.

Due to cases of burglaries, car theft, and vandalism, a housing association decided to build a video monitoring system. The facades of the buildings and the surrounding area are monitored by IP cameras Sunell K1691 with IR illuminators and mechanical IR cut filters. Modern solutions implemented in the cameras, in conjunction with 2-megapixel resolution, deliver high image quality both day and night. In order to control people entering / leaving the staircases there have been used analog vandal-proof Sunell cameras with increased horizontal resolution (900 TVL). Due to the small areas of ​​the staircases (3x3 m on each level), there was no need for using cameras with megapixel resolution there.

The architecture of the hybrid video surveillance system

The core of the LAN are ULTIPOWER N29986 PoE switches connected via optical links. The images from the cameras are recorded by Ultimax M72404 WD1 DVRs and Ultimax 2116 K2116 NVR. The DVRs are located in respective buildings, which improves reliability of the system. The images from all cameras are accessible on a PC running free VMS software, located in the monitoring center. The software allows for live monitoring and playback of materials recorded by the DVRs and the IP NVR. The managers and operators can also access the resources remotely via their smartphones running Android or iOS.

Overcoming obstacles between WLAN nodes.

In many situations it is impossible to achieve a direct link between two locations that should be wirelessly connected. However, the lack of line-of-sight does not eliminate wireless technology. In most cases the solution is to create an intermediate node and a combination of two point-to-point links. The devices creating the intermediate node (that are usually located side-by-side) can be connected directly via Ethernet cable.

The transmission between the two outermost nodes is enabled by the intermediate node
with two additional MikroTik access points

Twisted-pair cables - nomenclature, standards, parameters. Twisted-pair (balanced) cables are used to transmit signals in telecommunication systems and computer networks. Currently they are mainly used in analog telephony and Ethernet networks. Twisted-pair cables may consist of one or more pairs. The twisting strongly reduces the influence of external electromagnetic interference and mutual interference between the pairs, called crosstalk... more

Optical attenuators - application tips. Optical attenuators are passive elements of optical paths having the task to reduce signal levels to values acceptable for receivers. They are not used in systems with multimode fibers where the signal levels are comparatively low. The attenuators are necessary in the case of short links based on single-mode fibers and equipment... more

Diagram showing the use of attenuators (X, red) in a communication link with two media converters