It was no more than 11 minutes before we knew that the Perseverance rover had landed on Mars.

The Perseverance rover landed on the Red Planet on February 18. During the most advanced mission to Mars, launched on July 30, 2020, the rover worth more than $ 2 billion will search for extraterrestrial life.

Placing a space probe on the surface of the Red Planet is quite a challenge. There evidence for that is a large percentage of failures, such as the unsuccessful landing attempt of the European Schiaparelli lander in 2016. An interesting point is the delay in radio transmission due to the distance between Earth and Mars. All messages about the landing progress of the Perseverance rover reached Earth 11 minutes and 22 seconds later.

NASA members monitoring the landing process on the red planet

The first step was to free the Perseverance rover with the Ingenuity helicopter attached to it from the capsule that had delivered them close to Mars. After reaching the atmosphere (at a speed of about 19.5 thousand kmph) and crossing its upper layer, a parachute was deployed, interestingly, the time of launch was determined by the system analyzing the current altitude and distance from the landing site. After 20 seconds, the lower heat shield was detached, so that the radar could determine the exact altitude and enable the probe to establish and navigate to a safe landing site. Then, a minute before landing, the tailgate and parachutes were detached, and the rocket propulsion jets were launched to control the descend of the lander. Finally, the rover was lowered safely on nylon ropes by the skycrane. Experts are convinced that the next months will bring groundbreaking data for the exploration of Mars.

More about the rover and helicopter can be found in one of the previous issues of the Review.

Cabling termination in a telecom room.

The photos below show an example of a RACK cabinet at the end of data transmission cabling in a multi-family building with 70 apartments. The cabling and measurements were completed by Alarm House of Kielce.

The use of a RACK cabinet to terminate the cabling (coaxial, twisted pair and optical fibers) is the most common practice. RACK cabinets in size 42U enable convenient entry and termination of a large number of cables in a neat and practical manner. In the example presented, the following components from DIPOL were used:

The optical fiber part of the system was checked with the Grandway FHO3000-D26 L5828 OTDR. This tool has an appropriate dynamic range (you can read more about this parameter in one of the previous issues of the Review) for measurements in this type of networks. Due to short cable routes, it is particularly important to use a launch cable, e.g. L58415, to ensure correct measurement.

DVB-T/T2 digital terrestrial television – LTE interference filtering.

The 5G technology is the nearest future of the telecommunications market. However, for this to happen, appropriate infrastructure and allocation of RF bands is necessary. In most EU countries, work is underway to organize the radio spectrum and make the planned bands available for telecommunications services. To this end, the EU countries will have to free up the 700 MHz band and reorganize the DVB-T terrestrial multiplexes (frequency refarming) for the needs of mobile operators (5G services), as well as in connection with the transition to DVB-T2/HEVC broadcasting standard. Terrestrial TV systems commissioned in previous years are completely immune to interference from LTE transmitters. The highest-frequency TV channels with numbers 49 and 50 are most prone to interference. The image on the TV screen may freeze, colored stripes and squares (picture frameup) may appear. To exclude the interference of LTE transmitters on DVB-T/T2 reception, special internal and external filters were developed and patented.

LTE 700 Rejection Filter TERRA TF001 (mast mount) R81009

TF005, LTE 700 TERRA rejection filter

The problem of interference caused by LTE networks may affect all users of terrestrial TV - including those who receive programs on channels much lower than those mentioned above. Strong signals from local LTE transmitters can overdrive antenna amplifiers, blocking reception of DVB-T broadcasts. The good practice is to use rejection filters eliminating all unwanted signals at the input of any TV antenna system.

Virtual Host function in Hikvision NVRs.

The most convenient way to connect IP cameras in the monitoring system is to use the PoE standard. It streamlines the installation (one cable for power and data transmission). The camera is powered by a PoE switch, which can be independent or built into the recorder. A PoE switch or PoE recorder is best suited for systems with simple architecture. The cameras are Plug and Play devices (the recorder activates the cameras itself), and most of the parameters are set via the recorder. The cameras function in an internal, isolated network and cannot be accessed directly.

Small IP CCTV system based on PoE technology

If access to the cameras is required, e.g. to configure advanced functions that are not supported at the recorder level, you can enable a special Virtual Host function. It can be activated remotely via a browser or iVMS-4200, in the "Other" tab in advanced network settings. The recorder then performs routing between the camera and other devices. The connection of the network device with the camera is made with a special 6500x port where x is the channel number.

List of the recorder cameras. The link in the last column allows you to connect to IP
cameras and is visible after enabling the Virtual Host function.

Cost-effective home monitoring based on the IP system.

The diagram below shows a single-family home monitoring system based on Hikvision DS-2CD1023G0-I K17661 EasyIP Lite cameras with H.265 compression. The cameras are equipped with image sensors with a resolution of 2 MP and a fixed focal length ensuring a wide viewing angle of 103°. This model uses infrared LEDs in the EXIR 2.0 technology which allows for even illumination of the area at night. The DS-7604NI-K1/4P K22045 NVR with a 4-port PoE switch has been used to record the events. After connecting Hikvision IP cameras they will be automatically added to the NVR software, and the image will appear on the monitor. The NVR uses the WD Purple M89285 hard drive with a capacity of 3 TB. With the support of H.265 compression in the NVR and cameras, for continuous recording and 25 fps refresh rate, recordings from 4 cameras will be kept for over a month. To access the system from the local and external network, the recorder has been connected to the TP-Link C6 N3255 router. With to the support of the Hik-Connect cloud by Hikvision devices, access from an external network is extremely easy and does not require advanced knowledge of network issues. The Hikvision 21.5 "M2922 monitor displays the image directly from the NVR.

Monitoring of a detached house with Hikvision IP cameras.

WiFi 6 for business use.

The TP-LINK EAP620 HD N25691 access point provides a flexible, easy-to-install, manageable and secure business-class wireless network solution. It can be easily mounted to a wall or a ceiling. WLAN configuration and management are simplified through centralized software. The EAP620 HD provides captive portal and automatic RF management, making it ideal for high-density, demanding business environments, such as campuses, hotels, shopping malls, offices. The device works on the 2.4 GHz and 5 GHz bands in the 802.11ax (WiFi 6) standard.

Wireless access point TP-Link EAP620 HD 802.11ax AX1800, PoE N25691

DVB-S/S2 signal measurement – multiswitch system with Wide Band technology. The use of quatro converters in multiswitch systems to receive programs from two satellite positions (HotBird 13.0E and Astra 19.2E) requires installation of 8 RG-6 coaxial cables. With the use of Wide Band A98222 LNBs, this number can be reduced to four. Unlike standard quatro LNBs, the Wide Band LNB has two signal outputs (H/V polarization). It is based on a single local 10.41 GHz oscillator providing excellent performance in the entire frequency range of 290...2340 MHz...>>>more

The photo above shows the measurement of the satellite signal at the dSCR1 output of the SRM-522 R80522 multiswitch

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