Sprayed-on or printed solar cells

Let's paint the roof with special paints and we'll have a home power plant... This vision is not so awkward after the announcement that scientists have built a solar cell based on Colloidal Quantum Dot (CQD) films with a record-breaking efficiency of 7%, about 40% higher than that of the best previous devices using CQDs.

Although commercial cells based on traditional silicon technology have efficiency of 15-20%, which is up to three times higher than in the case of the new achievement, the sharp increase in CQD cell efficiency promises a number of interesting applications. They will result from the way of the production of the new cells, with the use of special paints or even just by printing using inkjet printers.

a) diagram of the solar cell made ​​out of colloidal quantum dot film
b) cross-section photographed by a scanning electron microscope

(source: physicsworld.com)

 

 

Colloidal Quantum Dot (CQD) films employ the recent developments in nanotechnology, particularly the phenomena taking place in so-called "Quantum dots" - ultra-thin semiconductor layer with unique light-capture properties. Quantum dots is an integrated thin film of thickness several to tens of nanometers, divided into cells ( "dots") of similar dimensions. It is worth to note that the wavelength of visible light ranges from 400 to 700 nm and 1 nanometer is one millionth of a millimeter.
 

 

The capturing of photons that increase the energy of electrons is the basis of all solar cells. The small surface and thickness of a "quantum dot" restricts the free movement of particles. By analogy to a shooting gallery, the photon has a greater chance to hit the immobilized electron instead of one constantly vibrating in a haphazard manner - hence the greater efficiency.
 

 

The problem is the selection of materials and mastering the technology, but the prospective performance levels are impressive, especially when combining existing and quantum technologies. In October, the United States Air Force commissioned Magnolia Solar to develop nanotechnology solutions for reaching the efficiency of solar cells intended for the defense and space industries close to 50%!

The total power used by humans is only about 0.02% of the solar radiation power reaching the Earth. The solar energy received by the Earth during six months equals the amount of energy contained in the estimated resources of the currently used fuels - coal, oil, gas and uranium. The total energy that reaches a horizontal surface throughout the year ranges from 600 kWh/m²/year in the Nordic  countries to more than 2500 kWh/m²/ year in central Africa. All the energy of solar radiation absorbed by the Earth, also used in any form by plants and animals, is transformed into heat and then emitted as infrared radiation into outer space. Development of a new generation of photovoltaic cells will allow for better absorption and use of solar energy.

The construction of a mechanical splice

Mechanical splices ULTIMODE FAST-MS1 are used for permanent connections of optical fibers without the need of employing fusion splicers. Everything the installer has to do before application of the splice is to remove the protective layers (jacket and aramid fibers), strip the buffer, clean the core cladding and cleave the fiber with the two active layers.

The main components of Ultimode FAST-MS1 L5550 mechanical splice

 

 

The prepared ends of the fibers to be spliced should then be inserted to the both sides of the L5550 mechanical splice. The body of the splice contains V-groove device with holes slightly larger than the fibers. These holes are filled with optical gel compensating for cutting imperfections and imprecise positioning. After full insertion of the fibers, they have to be locked with the buckles. The versatile design of the mechanical splice allows for splicing optical fibers with buffer coating diameters of 0.25 mm (using the included reducer) and 0.9 mm.

How to build a wired home network without the hassle of installing?

The solution is to use powerline Ethernet adapters TP-LINK TL-PA2010KIT N3363 allowing network connection through the existing power line. The pair or set of the powerline adapters is an ideal solution in every case where it is impossible or difficult to install Ethernet cables or the environment is not suitable for a wireless medium.

The adapters eliminate the need for installing UTP cables, drilling holes etc. In particular, they can be used to connect to the Internet such home appliances like televisions, satellite receivers, network players and other devices with network interfaces - there is no problem that the desired place does not ensure physical access to the LAN.

Powerline Ethernet adapters TP-LINK TL-PA2010KIT

DVB-T television and the Internet via one UTP cable

Low-voltage systems in office buildings often do not include TV antenna cables, but are usually fitted with structural cabling based on UTP cables. When some users want to connect televisions to watch DVB-T broadcasts, the lack of an RF distribution system may be a major obstacle (in many locations TV signals cannot be properly received using indoor antennas).

A unique solution to this problem is to use SIGNAL TV-LAN baluns for TV over UTP. The pair of the passive baluns can transmit analog/digital RF signals from an antenna placed in a suitable place via the existing UTP cable. The transmission is performed in parallel to the "normal" use of the cable for data transmission (LAN, Internet). The idea of using the Signal TV-LAN baluns is presented in the figure below.

Transmission of DVB-T and Ethernet signals over a single UTP cable with the use of R94200 baluns

Although the solution is based on point-to-point connection, it is possible to use multiple transmitter-receiver kits, even in combination with TV splitters and network switches. When the RF signal level after splitting is sufficient for further distribution, the signal can be sent over another UTP cable segment after a network switch, using additional pair of the baluns.

View of the Signal TV-LAN balun

Solutions based on the baluns are much more economical in comparison with deployment of additional systems based on coaxial cables or IPTV technology (the latter also requires extra network resources). They do not convert the original RF signals, only change the transmission medium.

Gigabit VPN router from TP-LINK

The TL-R600VPN SafeStream™  gigabit broadband VPN router provides Gigabit Ethernet connections both on WAN and LAN ports. The device supports multiple Virtual Private Networks (VPN) protocols, ensuring high security and excellent performance. This functionality is especially useful in office networks, allowing for remote access to resources while maintaining maximum security. In addition, the security policies used in the TL-R600VPN router, such as SPI firewall, DoS attack protection, and IP-MAC binding help protect the network against the most common attacks. TL-R600VPN is the ideal device for small offices that need cost-effective and reliable VPN solutions.

 

The VPN tunnels supported by the TL-R600VPN router provide secure links between client terminals through a public network (usually the Internet), with the use of IPsec and PPTP protocols. The router can also handle IPsec/PPTP/L2TP "pass-through" traffic. The hardware-based VPN engine can handle up to 20 IPsec LAN-to-LAN and 16 PPTP VPN connections.

The VPN TP-LINK TL-R600VPN SafeStream N3385 router

HTTP streaming on Android - commercial deployment of MPEG-DASH

On November 6, 2012, Fraunhofer IIS and BuyDRM presented in Los Angeles one of the first commercial multimedia streaming systems based on MPEG-DASH ISO standard and Microsoft's PlayReady DRM, to be used on mobile devices running Android operating system. The showcase organized together with HBO, the content provider, proved the tendency of the industry to utilize the potential of mobile devices as "second screens" and content delivery means. According to media analysts forecasts, tablets and smartphones will increasingly complement or replace televisions.

The innovative solution from Fraunhofer IIS and BuyDRM allows secure transmission of surround sound and video, automatically adjusting the bitrates to changing network conditions. Currently, the solution is available for HBO GO subscribers using Android devices. The application is as easy as playing a BluRay or DVD.

 

 

MPEG-DASH (Dynamic Adaptive Streaming over HTTP) was approved in November 2011. This standard for streaming media is to ensure the highest possible quality (QoE - Quality of Experience) and unify various currently used systems such as Microsoft's Smooth Streaming, Adobe's HTTP Dynamic Streaming and Apple's HTTP Live Streaming. The biggest advantage of MPEG-DASH is the fact that the content is made available as segments at a variety of different bit rates. The MPEG-DASH clients select segments with the highest bit rates possible for seamless playback, avoiding problems with stalls or rebuffering in less efficient networks.

MPEG-DASH was one of the solutions promoted by Fraunhofer IIS during this year's IBC conference in Amsterdam. Fraunhofer IIS Audio & Multimedia division, based in Erlangen, Germany, has a 20 years of experience in audio compression technology and remains a leading innovator of multimedia systems. It has a significant contribution to the development of MP3 and AAC (Advanced Audio Coding) used to transmit and broadcast streams in over 5 billion devices worldwide. Its codecs are used in HTML 5, Apple Safari, Microsoft Internet Explorer 9 and Google Chrome. Fraunhofer IIS also has been developing MPEG Surround to support multiple audio channels, utilized in the project described at the outset.

There is no doubt that the market for broadband streaming will significantly grow over the coming years. Adaptive streaming techniques, such as MPEG-DASH, will greatly accelerate this process.

The triumph of intelligent multipoint-to-multipoint wireless mesh architecture

The world's longest wireless network based on mesh technology has been deployed in Thailand. The network, built by an American company Firetide, covers a distance of 372 km. It has been conceived as a kind of a gift from Thailand’s Royal Irrigation Department to the 84 year old King of Thailand, Bhumibol Adulyadej. The network is to provide images of the floodplains of the river Chao Phraya. Due to his age, the king is no longer able to oversee the monitored areas in person. The implementation of such a gift turned out to be technically challenging.

The total cost of the world's longest wireless mesh network is about 2 million USD. However, this sum of money is not large considering the fact that during the last monsoon season the network gave the chance to save hundreds of people from flooding. The Thai network belongs to the group of early warning systems for floods.

The images from the cameras are available on the Internet at this address.

Google Maps application provides information on the location of each camera.

 

 

The entire network has been built based on mesh technology. The main advantages of this type of network architecture include auto-configuration and full redundancy in the case of a node/link failure. The latter feature is guaranteed by an automatic change of the route of data packets, which is particularly important in so large and responsible systems.
The main components of the network are 64 Firetide HotPort 7020 wireless mesh nodes and 27 Panasonic PTZ WV-SW395E cameras. The distances between nodes range from 20 to 45 km. The total throughput of the network is as much as 240 Mbps, with node-to-node latency below 1 ms.

High throughput is achieved by the use of Firetide HotPort 7020 mesh nodes, compliant with 802.11n standard and implementing MIMO multi-antenna technology, with 40 MHz wide channels. The routing of the frames is based on proprietary AutoMesh mechanism, based on the 802.11s standard for wireless mesh networks approved in the last year. [source: firetide.com]

Last year's approval of the 802.11s standard can accelerate the popularization of wireless mesh technology. Until now, mesh networks were mostly implemented as experimental projects, not having much in common with the commercial market. Today, in addition to the large-scale undertaking in Thailand, some more "ordinary" projects are carried out, such as the city video surveillance system in Altanta, with 110 cameras. Time will tell whether mesh technology will be more popular on European markets.

Cloud-based video monitoring is gaining popularity.

Securicorp Components Ltd., a UK-based security services company, has launched a monitoring service based on the concept of cloud computing, where the resources, software, and data storage system are available in the cloud. Although cloud video surveillance is a hot subject in the industry, the service is one of the first market offerings for companies and individuals.

The clients will control and manage their systems online, through account usernames and passwords, the video data will be stored on external servers - "in the cloud". The installation and configuration of the IP cameras on site will be as simple as possible - the users don't need to know technical details. To provide the cloud solution, Securicorp has partnered with telecoms, data centers, Internet service providers, and retail companies.

 

So, the whole system of the individual user exists in the virtual world, with automatic update to the latest version and optimization in the background, and surveillance data stored on external servers located outside the monitored facilities. The existence of the system in the form of a flexible digital platform will allow anyone to select features that are really needed, without paying for unnecessary functions.

 

Securicorp and other suppliers of CCTV solutions use ready-made software solutions that allow for the implementation of CCTV in the cloud. The first solution dedicated for ISPs, telecom operators, and security services companies has been offered by NeoVSP. The OVS™ (Online Video Surveillance) belongs to the Video Surveillance as a Service (VSaaS) solutions that minimize the clients' involvement in the network architecture and equipment, usually aside from the cameras. Similar solutions are offered by Iveda Solutions, OzVision, Connexed, iControl.

The change in thinking of CCTV video surveillance a service rather than the physical system opens the door to long-awaited features, including the most expected one: intelligent image analysis. The amount of gathered data, even in medium-sized systems, is so great that also the most modern video monitoring systems have to be treated more as archives than sources of live information. The application of cloud computing technology provides almost unlimited possibilities. It is only a matter of time when IT specialists create algorithms with artificial intelligence techniques allowing for autonomous early detection of real threats.