Antennas in Turkey

The population of Turkey is about 68 million. The gross national product per capita is about 6700 USD.

The number of registered cell phones is about 26 million. The service of Global System for Mobile Communications (GSM) is provided by four operators Turkcell, Telsim, Aria, Aycell.

Transmission of TV programs began in the year 1968. There are 4 national public TV programs, 16 private TV programs, and 4 digital and SAT TV packages to chose from. In 1990 the government monopoly on TV programming broadcasting was crushed and from that moment on Turkey has been experiencing a real boom in the private TV sector.

The first broadcasting in Turkish started in 1990. Presently programs in Turkish are reaching all continents thanks to the satellite like Turksat 1C, Eutelsat W3, Eutelsat HotBird-6, Thaicom-3, Optus B3, PAS 8, Intelsat 907, Telstar 5

Internet services are still in their infancy - the number of the Internet users is about 4.4 million, in Poland about 8 million.

German radar stations during WWII

The base of FuMG-65 Würzburg-Riese radar station used by Luftwaffe in Wroclaw, Poland. The station belonged to Bischwitz radio engineering unit.

Among several solutions used by Germans the most popular was the "Himmelbett" radio system - consisted of two FuMG 65 "Würzburg-Riese" radars, Freya radar, and main Seeburg station.

The Freya radar had a maximum range of about 200 kilometers and was used for observation, in concert with two gun laying radars - "Würzburg-Riese", directing fighter squadrons at the arriving bombers.

The maximum range of FuMG 65 was 70 km. The radars were manufactured by Telefunken and equipped with antennas of 7.5m diameter. In total there were about 1500 such stations in Europe. Many of them were deployed in occupied Poland, mainly in the north and south.

In our times we can only encounter characteristic concrete foundations in hexagonal form. They were the bases for the metal constructions of FuMG 65 weighting nearly 20 tons. More informations you can find: http://weeklyreview.dipolnet.com/inf_dipo_2008_06.htm

In Poland there were more than 100 Luftwaffe radio stations, in Europe there were more than 1500 radio stations. There is a picture on the page: http://weeklyreview.dipolnet.com/inf_dipo_2008_06.htm that shows Kozieglowy in Silesia, Poland. The concrete base for German radar - Luftwaffe FuMG-65 Würzburg-Riese.

The hierarchy of radar stations had three levels: Stellung 1. Ordnung, Stellung 2. Ordnung, Stellung 3. Ordnung. Stations with the priority 1. Ordnung had to collect informations from 2. and 3. Ordnung.

The first mention of radar on the Isle of Wight took place in September 1935,

In June 1937, radar was ready for use as a weapon of war. In July the Dover Chain Home station in July 1937 was open.

Between 1940 and 1942, Britain had to find out exactly how far advanced German radar was, and so at Bruneval in France a raid was planned on the German radar installation.

The real raid on Bruneval on 17 February in 1942 was a real success.

Mobile World Congress - Barcelona 2008

Power of technology. The congress was held between February 11 and 14, organized by GSM Association (GSMA).

In Barcelona there were 1 290 companie about 55 000 visitors saw their stands. The audience that took part in the accompanying conferences was estimated at 8 000 people.
So high interest in this technology arises out of the scale of the market. Enormous investments and mass market encourage manufacturers, scientists, and marketing specialists to develop new and improved products.

This year the interest focused on LTE technology (Long Term Evolution). It is the newly adopted standard (January 2008). It should be commercially launched on the market in 2009, and able to compete even with fiber-optic technology (in mass-market applications). It is possible due to practical transfers ca 100 Mbps (theoretical limits reach 300 Mbps!).

Analyzing the market potential of various technologies or services according to the number of conferences, the most promising areas seem to be payments via mobile phones and mobile TV.

There were given Global Mobile Awards for the products connected with mobile technologies listed below:

* Best mobile handset/device: SonyEricsson for W910 Walkman Phone and 3UK for 3 Skypephone, the first GSM mobile that supports Skype;
* RAD Data Communications - for LA-130 Cell Gateway, linking wired and mobile systems;
* Airtel - for mChek service providing access via mobile phone to credit cards and bank accounts, including operations, after entering 6-digit PIN (application of USSD capability - Unstructured Supplementary Service Data).

USSD is instant messaging type phone service, not employing SMSC (Short Message Service Center), used for example to query the available balance, to recharge the credit etc. in pre-paid GSM services. The function of a code depends on what kind of services the operator has made available.

Leonardo da Vinci

While performing some routine conservation works in the Czartorysky Museum in Cracow, a group of experts of the Historical Artifact and Relic Preservation Organization have discovered some images that were hidden in one of the paintings by Leonardo da Vinci. As it is a well-known fact, this genius invented the bicycle, helicopter, and even submarine. Now, it turns out that the "antennology" has finally found its forefather too, and its history is much longer than previously believed. A commission composed of art historians has decided to restore the picture back to its familiar motif so that it could look like before the conservation work. If that hadn't been done, the cost of renaming the painting from "Lady with an Ermine" to "Lady with an Antenna" in all art books and art guides would have outgrown the budget of the Ministry of Culture and National Heritage. However, we've managed to take this unique photo. :-)))

Winter

The highest free standing tower (without ropes)

N.C. Tower, Toronto
built in 1976, 553.33 m

Basic informations about WLAN

WLAN (Wireless Local Area Network) means technology which allows to build wireless data networks with satisfactory parameters and quite large ranges of operation at a low cost.

Potentiality of WLANs

• wireless access to local network in home, office etc.
• wireless access to the Net in public space: airports, stations, cafes etc. (hot-spot)
• wireless point-to-point links (connecting LAN networks, telemetry, remote control, remote monitoring)
• wireless access to the Internet (both in cities and in the country)
• emergency communications link (duplication of wired network)

WLAN standards

• 802.11a - in 5 GHz band, transfer rate up to 54 Mbps
• 802.11b - in 2.4 GHz band, transfer rate up to 11 Mbps
• 802.11g - in 2.4 GHz band, transfer rate up to 54 Mbps

However, there are also used other standards:

• 802.11f - IAPP - Inter Access Point Protocol - for cooperation between access points
• 802.11i - standard defining new security methods in wireless networks
• 802.11n - standard for transmitting multimedia in homes using MIMO technology, up to 300 Mbps
• 802.11e - standard defining QoS - support for high quality of services
• 802.16 - WiMax standard for backbone networks of high capacity

Wireless network range

It should be realized that the range of a wireless network depends on many factors; we can have an influence on some of them and the rest is unknown. The range of wireless network depends on:

1. Factors related to used devices:

• output power (it has been decided by the manufacturer)
• cable attenuation (depends on the cable and its length)
• gain of antennas (given by the manufacturer)
• sensitivity of devices (given by the manufacturer)

2. External factors:

• attenuation between antennas (can be estimated basing on FSL model)
• interferences from other devices (can't be predicted - some additional margin of safety needs to be provided to compensate these interferences)
• influence of physical barriers (walls, trees)

Propagation of radio waves

Fresnel zone - Fresnel zone is one of the most important conceptions connected with propagation of electromagnetic waves, which is indispensable to assess parameters of wireless link. It is the area actively participating in transmission of radio signal energy. Shape of this area is an ellipse in longitudinal section, and circle in cross-section. Radius of this circle is a function of the ratio of distances between antennas - it has the maximum value in the middle of the link. The importance of first Fresnel zone comes from the fact that almost all energy of the signal is conveyed via this space.