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

The IEEE 802.11n standard ratified! The 802.11n standard, allowing for data transmission with rates up to 600 Mbps, is planned as the base for home multimedia transmissions.
The equipment based on the new standard has been available on the market for several years, but is really popular after the introduction of the "Draft 2.0", i.e. the set of requirements consistent with the planned target version. This allowed manufacturers to offer devices compatible with final standard.
Initially, the n-like devices operated at speeds up to 100 Mbps, and products of different brands did not work together. With progress in technology and standardization, the speed was increasing, and devices from different manufacturers were becoming compatible.

Cooperation of 802.11n devices with previous products:

Transmission speeds of up to 600 Mbps require the use of multiple channels simultaneously. Despite the application of a safeguard mechanism, the transmission is susceptible to interference from networks based on other standards, in particular 802.11 b/g.

"Engagingly about antennas" - the last days for sending photos to the contest. At the end of the competition we get true gems of "antenna art".
We look forward to your entries till September 30.
We invite you to familiarize yourself with the entries that we have received so far.

Signal - new line of radial multiswitches. There is a change in our offer for small and medium SMATV systems. The new family of multiswitches ensures better quality of the devices that allow distribution of satellite and terrestrial signals in one-family houses and small apartment buildings. The series includes the following models:

Number of outputs	5 inputs	9 inputs
4	R6944504	R6944804
8	R6944508	R6944808
12	R6944512	R6944812
16	R6944516	R6944816

 

9/12 multiswitch Signal MP-0912
R6944812

Operating parameters of the presented devices are similar to those of a higher-class equipment. The most important include:

The multiswitches pass DiSEqC 2.0 and ToneBurst control signals. A typical application of R6944804 multiswitch is shown in the diagram below.

The aim is to provide signals from Hotbird and Astra satellites and terrestrial DVB-T and analog TV stations to the three outlets (one of the receivers has double tuner and features PVR function - this requires a reservation of two multiswitch outputs).

Example application of the Signal MP-0904 multiswitch (R6944804)

The simple system shown above is based on radial Signal multiswitch that can distribute DVB-S/S2 digital satellite programs (including HDTV) and terrestrial digital (DVB-T) and analog TV broadcasts. Currently, due to the growing popularity of DVB-T platform, manufacturers equip TV sets with digital terrestrial tuners. If some television has no built-in DVB-T tuner, the user can employ an external device (Set-Top-Box), e.g. Ferguson FT-8300 HD, or - like in the example above - Ferguson Ariva HDcombo A99381 (DVB-S and DVB-T receiver).

FHSS - a few words on WiFi - part 5. FHSS (Frequency Hopping Spread Spectrum) is another physical layer of the IEEE 802.11 standard.
The frequency of the carrier wave in FHSS is periodically (in regular time intervals) changing by discrete values (using a pseudorandom sequence known to both the transmitter and receiver). The time period when the frequency is constant (dwell time) is sufficient for sending several data bits. The consecutive carrier waves are modulated with frequency shift keying, which results in narrow-band signals.
The list of frequencies of the carrier wave is called frequency-hopping code (FH). The spectrum of such a signal, observed for the time longer than the period of the FH sequence is a set of discrete bars that can bypass the frequencies of interfering signals.
The advantage of FHSS systems is the possibility of retransmission of distorted messages at different frequencies in subsequent jumps. As mentioned, before the data transmission can take place, the transmitter and receiver must adopt the same hoping pattern, i.e. the sequence of channels that will be used during the transmission. If one of the channels does not allow proper communication (because of interference), the data transmission is continued on another frequency in the next jump/s.

Frequency Hopping Spread Spectrum

In the case of FHSS, the IEEE 802.11 standard provides 79 carrier frequencies (channels) with 1 MHz spacing, from 2402 MHz to 2480 MHz. Each of these carriers is modulated using GFSK. Possible transmission speeds are 1 Mbps and 2 Mbps. 78 strings of hoping sequences have been defined. The sequences have been further divided into 3 subsets with 26 strings. Sequences from the same subset can be assigned to systems that are close to each other. Because they are grouped together, the probability of collision is minimal. In theory, up to 26 systems can exist close to each other, but in practice, due to the number of collisions, about 12 is considered as a safe number. An important factor is the minimal difference between the momentary frequencies in different systems. Due to the limitations in selectivity of receivers, the difference should not be less than 6 MHz.

Faster Internet - ULTIMODE media converters. Ethernet media converters allow to change electrical signals (Ethernet data stream) coming via typical STP/UTP cables into modulated light signals transmitted via fiber optic cables, with data rates up to 1Gbps.
The ULTIMODE media converters are fully compatible with IEEE 802.3 and IEEE 802.3u standards. They have MDI/MDIX auto detection feature and automatically find and set the fastest connection speed and mode. "Store and forward" mechanism allows to verify the received data using checksum function.

Needs and requirements of Internet users are constantly increasing. Telecommunications operators, wishing to satisfy the needs of customers, must provide them with a high-speed Internet and other broadband services, including TV and video transmission. Only fiber-optic technology brought directly to the end user's home or site (FTTH - Fiber To The Home) is able to provide all the services simultaneously and practically without any limits.
Media converters are widely used for the transmission of Ethernet signals over long distances and in areas exposed to harsh weather conditions. Optical fibers provide full electrical insulation and resistance to electromagnetic interference. Media converters are primarily used to connect building LANs (e.g. of scattered buildings of one corporation).

Example application of ULTIMODE media converters

NUUO DVRs - a new standard of video surveillance. NVR (Network Video Recorder) NUUO is innovative Plug &Play device for full management of IP CCTV system. The main functions include live monitoring, recording of video streams, playback of the archives. This flexible NVR platform allows multi-server multi-client operation. NUUO NV-4080 K4108 allows to record video streams from megapixel (up to 5 Mpix) and standard-resolution cameras, with frame rates up to 25 fps. Due to Linux OS, it ensures stable operation and resistance to computer viruses.
NUUO NVRs are used in all kinds of maintenance-free systems. In this kind of small- and medium-size systems the NVR can be connected to any node of IP network and provide service for a number of customers (clients) with hierarchical access rights. The access to the system is needed only in certain situations (e.g. alarms). Application of NVRs also means a significant reduction in the costs of the system (no need for a computer with high computing power). Such systems are suitable for surveillance of offices, factories, warehouses, stores, businesses, various buildings etc.
The system is operated only remotely (via IP network). There is no need to create or define a monitoring center, because its functions can be performed from any point of the network. The connection is via Internet Explorer or client software. The former solution is convenient for its simplicity (no need to install additional applications), while the latter makes it possible to work on several servers at once.

The structure of IP CCTV system based on NUUO NVR

"ULTI-monitoring" in cities. Building extensive monitoring system, such as video surveillance system in a city, one should use proven solutions and systems approach. Many installers have bad experiences with the devices which independently operate very well, but have problems with communicating each other. Therefore, only advanced and tested solutions can ensure proper operation of the system.

Elements of CCTV systems verified in urban and other large installations:

The main features of a modern monitoring system are:

"ULTI-monitoring" - a comprehensive video surveillance system

New video clips in ACTi library. We invite everyone to the Library of Megapixel ACTi Video Clips, with new megapixel materials: the K1315 camera image from an office, recorded at night, entrance to a parking lot monitored with K1511 camera, and view of a park through the K1514 camera.

Distinguishing features of TRANS-DATA antennas:

Economic router integrated with Access Point - an ideal solution for home users. TP-LINK TL-WR340G 54 Mbps N2952 is a wireless router, integrating router, firewall, and access point. It has been designed to provide internet connectivity to small and medium businesses, as well as to private users in apartments and one-family homes.
TP-Link TL-WR340G enables the user to build wireless network quickly and easily and to share Internet connection among a number of computers - ensuring additional protection due to built-in firewall.

TL-WR340G integrates access point, broadband router (for xDSL or cable modem), and 4-port FastEthernet switch. It is an ideal and economical solution for home users.

TL-WR340G ensures advanced access control, NAT, and its DHCP server supports static assignment of IP addresses. It is possible to use virtual servers, DMZ, remote managing and logging.

Recommended articles from our Library:

ULTISYSTEM - advanced surveillance software. The ULTISYSTEM software has functionality of professional NVR (Network Video Recorder) that manages IP CCTV systems based on transmission of surveillance data in Ethernet network. The software can fully integrate a whole set of IP CCTV devices (IP cameras, video servers, DVRs). Application of video servers and ULTIMAX DVRs allows to utilize any analog cameras. The distinguishing feature of this software is support for megapixel IP cameras...


Instructions on how to properly protect connections
with self-amalgamating tape. Self-amalgamating SCAPA 2501 tape is based on PIB (Polyisobutylene) rubber. It is a versatile material for waterproofing, corrosion protection, jointing and repair of cables - used indoors and outdoors. Product properties and correct application ensure waterproof connections (for fresh and sea water) in a wide range of temperatures...


ULTIAIR - efficient and secure wireless data transmission. ULTIAIR is a family of professional Access Points, designed for efficient long-term outdoor operation. Integration of the transceiver and antenna into one weather-resistant housing enables the installer to perform the job quickly, without additional operations...


Index of published issues