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No. 9/2020 (March 2, 2020)
Can drones provide internet coverage?
In 2017, Rahul Tiwari, a 22-year-old student at Purdue University in the state of Indiana, USA, hit on an ingenious way to bring internet coverage to remote areas with the use of drones. Telelift is an attempt to create a flying cellphone tower based on table-size drones attached to the ground by a long wire. Connected to solar panels or a power source, the devices can supposedly stay in the air for at least a month at an altitude of c. 60 m.
A drone designed for internet distribution
Initially, Tiwari planned to use his drones as flying watchtowers to combat illegal poaching in Africa, but when he talked to industry experts, he realized they had a much bigger potential. With 4G routers placed on top, the drones could bring internet anywhere. Tiwari's Minnesota-based start-up, Spooky Action, now wants to launch Telelift in areas with poor internet coverage, beginning in Kenya, Niger, Botswana, and Senegal. According to GSMA, an industry organization that represents the interests of mobile network operators worldwide, roughly 4 billion people around the world still do not have internet access.
Each drone can provide coverage for several hundred people within a radius of 32 to 48 kilometers. Vast, desert areas can do with just one drone, while suburbs may require several. However, Telelift faces a number of potential obstacles. Civil aviation authorities are becoming more alarmed by the issue of unmanned aerial vehicles, motor failures, and busy air spaces. Sam Twala from a South African consulting company, NTSU Aviation solutions, however, reassures the regulators that Telelift has a back-up battery and control system, which allows it to stay in the air and land safely even if the tether is cut. Telelift looks like an excellent solution for emergency response or search and rescue. Continuous use, however, could be problematic, since many drone components are not designed for 24/7 operation in extreme conditions. To make sure they can withstand the African heat, the drones must be made with enhanced engines and materials.
A multiswitch system in a multi-family building.
The most flexible multiswitch installations in multi-story buildings are based on 5-cable systems. The 5-cable bus is split into subnetworks for apartments in each staircase, and then on each floor, by a suitable tap providing signals to a "story" multiswitch. This allows to build a SMATV system with a large potential for further expansion.The MV-5XX TERRA 5-input series features devices designed for use as the "story" or "floor" multiswitches in such 5-cable systems, characterized by the grouping of outputs with different output levels, which enables installers to equalize signals in outlets located at different distances from the multiswitch. Additionally, the multiswitches have a built-in compensation of the signal loss at higher frequencies in the distribution cables.
An example of a SMATV system in a multi-family building (4 staircases, 4 floors) - one satellite position. The system is based on a bus topology, using splitters (SDQ-508 R70520 and SD-504 R70515), taps (SD-515 R70517 and SD-510 R70516), and multiswitches from the MV-5XX TERRA series. All active components of the system are powered from the SA-51 R70501 broadband amplifier.
More examples of SMATV systems in multi-family buildings.
More examples of SMATV systems in multi-family buildings.
Bus topology offers a number of advantages over popular cascade solutions. The most important is that it serves to minimize the impact of a failure in one network segment on the rest of the system. In cascade systems, a failure of one device leads to signal loss in the system at large; the greater the system, the more difficult it becomes to locate the source of the failure. In contrast, in TERRA's solution, the signal is lost only in outlets connected to the multiswitch in question, while the rest of the network remains unaffected.
Intelligent remote search function in Hikvision HD-TVI DVRs.
HD-TVI DVRs offer an intelligent search function, available both through local access and remotely via a web browser.
An example of intelligent video analysis. The recordings were searched for instances of yellow line crossing. The DVR captured the moving object within a green rectangle. The moments when it crossed the line are marked red on the timeline (the blue indicates a continuous recording mode).
Video analysis can detect:
- line crossings,
- intrusions into a selected area,
- motion (within the whole field of view).
Once the analysis is complete, the detected events are marked red on the timeline. This allows the operator to locate the relevant video coverage quickly and effectively. In order to detect line crossings and intrusions into selected area(s), the VCA functions must be active at the time of recording (no matter how they are set up). This is not required in the case of full-screen motion detection.
Certified RACK cabinets.
Until recently, RACK cabinets have only been used in professional telecommunications systems and server rooms. Today, smaller cabinets can be found in nearly all building installations, as well as home systems. They are an ideal solution for terminating telecommunications cable systems and installing active devices.When choosing accessories to go with rack cabinets, pay attention to their compatibility with specific models. Some components may fit one but not another cabinet, e.g. due to a greater depth or a different component mounting method (e.g. a fan).To address the problem, the DIPOL e-Store offers a simple mechanism based on a list of compatible accessories for selected RACK cabinets. In order to use it, open the page of the required RACK cabinet, e.g. R912020, and then click the "Add accessories" button on the right.
Hanging RACK cabinets are ideal for building and home systems.
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A document to certify the compliance of the cabinet with general safety requirements contained in Chapter II of the General Product Safety Directive (2001/95/EC) of 3 December 2001 and in the guidelines of the EN 60950-1:2007 international standard, issued by KOMAG INSTITUTE OF MINING TECHNOLOGY
Users can import a list of license plate numbers for which the camera will activate the alarm output to open the boom gate. This will automate and facilitate entry into the neighborhood. The maximum capacity of the list is limited to 2048 numbers, which can then be assigned either to the white (allowed) or the black (banned) list. The process of adding and deleting license plates is very simple. Log in to your camera and open the Configuration -> Road Traffic -> Blacklist & Whitelist tab, where you will find an Export button. The button allows you to export the current license plate list (as an *.xls file), which should be saved on the hard drive. Open the file editing menu and fill in three fields:
- N.O. - ordinal number,
- Plate Num - vehicle license number,
- Group (0 - black list, 1 - white list).
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*.xls file editing window with the list of license plates. |
When you finish editing the list and save the changes, go back to the Configuration -> Road Traffic -> Blacklist & Whitelist tab, click the Browse button, indicate the location of the saved file, and then click Import to upload the list to the camera. To finish the setup, go to the Configuration -> Road Traffic -> Detection Configuration tab, activate vehicle detection, select the detection area, configure the schedule, and specify the desired response to vehicles from the white list and the black list (e.g. triggering the alarm output).
Example of a 1U RACK distribution frame.
Being able to handle a fusion splicer is no doubt essential when building fiber-optic systems. However, installers quickly realize that it is not te splicing as such that poses a problem. While it is important to properly prepare, clean, and cut the fibers, the real challenge is the correct and aesthetic termination of all cables in distribution frames, boxes, trays, etc. Installers must be able to properly prepare and measure the spare lengths of the fibers and secure them in a way that allows for future system correction and expansion. Each distribution frame/box will require a slightly different approach, but the general guidelines and procedures are usually the same.When terminating fiber-optic cables in a distribution frame, remember to:
- leave a spare length of the cable in front of the distribution box,
- connect the cable at the inlet opening (first measure out the appropriate length of the cable to be accommodated in the distribution box),
- process the cable and insert it into the distribution box,
- if the cable has a loose tube construction, attach the tube at the input of the splice tray,
- allow a spare length of fibers to enable their convenient splicing outside the box,
- insert the fibers into the splice tray and perform a precise measurement to make sure that the sleeves fit neatly into the designated spots,
- in the same way, measure the pigtails to avoid any redundant coils in the box,
- perform the splicing,
- insert the cable fibers and pigtails into the tray; if possible, leave a spare length of fibers and pigtails on separate rings,
- attach the pigtails at the output of the tray,
- connect pigtails to the front panel.
An example of a simple RACK 1U distribution frame
The image above shows a fiber-optic distribution frame that accommodates two universal 8J cables (2 fibers). The fibers are crossed over on the front panel. For testing purposes, one of the pigtails has a PC polish (blue) to enable the assessment of the impact of PC <-> APC connections on signal attenuation.
 | Fiber-optic Cable: Fibertechnic DAC Z-XOTKtcdD 2J L79202 is designed for installataion directly in the ground. It has a HDPE sheath with high crush resistance (4000 N), which also makes it resistant to low temperatures. It can be employed on the last mile of a FTTH system, as well as in any installation that requires terrestrial cables, where casing pipes cannot be used for additional protection. | |
 | Ceiling IP Camera: Hikvision DS-2CD2347G1-L K00311 is an ideal solution for all those who wish to expand their CCTV systems to include a camera that allows to monitor the scene in color mode around the clock and thus detect all the necessary details. | |
 | Compact IP Camera: Hikvision DS-2CD2T47G1-L K04471 belongs to the ColorVu series of cameras that allow to monitor the scene in color mode around the clock and thus detect all the necessary details. | |
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