Point to Multipoint Connection

The layout is also frequently encountered network are point-to-multipoint. If some node2 speak to the center access, this is the application of point-to-multipoint. A typical example of the layout of the point-to-multipoint is the use of wireless access points that provide connectivity to multiple laptops. Laptops do not communicate with each other directly, but must be in the region access point to be able to use the network.

Network point-to-multipoint can also be applied to our previous example at the university. For example, a remote building on the hill is connected to the center of the campus using a point-to-point. Rather than setting up multiple connections point-to-point to distribute the Internet connection, an antenna can be used as long as seen by some of these remote buildings. This is a classic example of the wide area connection point (a remote area on the hill) to multipoint (many buildings in the valley).

Please note that there are some performance issues with the use of the connection point-to-multipoint for very long distances, which will be explained later in this chapter. Type of connection may be used in some circumstances, but not to make the classic mistake by installing a radio tower with a big power in the middle of the city and expect to serve thousands of customers, like you would do with an FM radio station. As we shall see, two-way data networks behave very differently from broadcast radio.

Ref : http://opensource.telkomspeedy.com/wiki/index.php/WNDW:_Point-to-multipoint

Point to Point Connection

Connection Point-to-point usually provides an Internet connection where other access is not available. One side of the connection point-to-point Internet connection, while others use the connection to reach the Internet. For example, a university might have a frame relay or VSAT connection is fast in the middle of campus, but unable to make the connection to the important buildings that are outside the campus. If the main building on campus has an open view to the outside of campus buildings, the connection point-to-point can be used to make the two buildings are connected. This can be either additional or even replace dial-up connection. With proper antennas and line of sight, the connection point-to-point exceeding thirty kilometers is possible.

Of course, once a connection is point-to-point is created, much can be done to expand the network further. If the building is much as in the example at the top of a high hill, may be able to see other important locations that can not be seen directly from the central campus. By installing the connection point-to-point in remote areas, other nodes can join the network and use the internet connection from the center.

Connection Point-to-point does not necessarily have to involve Internet access. Suppose you have to physically drive to a remote weather monitoring station, which is high in the hills, in order to collect data and record from time to time. You can link these places by using the connection point-to-point, which allows monitoring of data in realtime, without having to travel to the site. Wireless networks can provide a large enough bandwidth to carry large amounts of data (including audio and video) between two points that have connections to each, even without any direct connection to the internet.

Ref : http://opensource.telkomspeedy.com/wiki/index.php/WNDW:_Point-to-point

IEEE 802.11 Protocol

Protocol	Frequency	Maximum Speed
IEEE 802.11	2.4GHz	2Mbps
IEEE 802.11a	5GHz	54Mbps
IEEE 802.11a 2X	5GHz	108Mbps
IEEE 802.11b	2.4GHz	11Mbps
IEEE 802.11b+	2.4GHz	22Mbps
IEEE 802.11g	2.4GHz	54Mbps
IEEE 802.11n	2.4GHz	120Mbps

Antenna Type

Basically we have several types of antennas that can be used in Wireless Metropolitan Area Network (WMAN), namely:

• Omnidirectional Antenna - Antenna is usually used in Access Point (AP). This type antenna has a 360-degree radiation pattern.
• Sectoral antennas are usually used in Access Point (AP). Usually have a higher gain than omnidirectional antenna, but the area is on the cover is usually only about 90-180 degrees.
• Directional Antenna (Antenna Steering) is usually used on the client side. Usually has a very high gain and are directed to the Access Point (AP). The example used in the Wireless Internet, such as satellite dish antennas, Wajanbolic e-goen or antenna cans.

Some countries, including Indonesia, requires that all radio systems in the certification. This means that only the antenna on the test & in the certification along with his radio that can be used. Unfortunately, the application of such rules would be very difficult because it is very easy to change the configuration tool.

Ref : http://opensource.telkomspeedy.com/wiki/index.php/WiFi:_Tipe_Antenna

Sectoral Antenna

Sectoral Antenna sometimes called the Antenna Patch Panel is basically not much different with omni antenna. Typically used for connection to the Access Point Point-to-Multi-Point (P2MP). Generally sectoral antenna has vertical polarization, some of which also has a horizontal polarization.

Sectoral Antenna reinforcement generally have higher than about 10-19 dBi omni antenna. Very good to provide service in areas within a distance of 6-8 km. Strengthening of sectoral antenna height is usually in compensation to the width of a narrow radiation pattern of 45-180 degrees. Clearly, in the service area that can become more narrow, and this is very profitable.

In the figure below show the sectoral antenna radiation pattern. In general, more radiation antenna to the antenna face, not a lot of radiation behind the antenna sector. Radiation vertical pieces do not vary much with omni antenna.

Sectoral Antenna usually put on top of a tall tower, therefore, usually on tilt a bit to provide services to areas underneath.

Ref : 

http://opensource.telkomspeedy.com/wiki/index.php/Antenna_Sectoral

http://en.wikipedia.org/wiki/Sector_antenna

Omnidirectional antenna

An omnidirectional antenna is an antenna which radiates power uniformly in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis. This radiation pattern is often described as "donut shaped". Omnidirectional antennas oriented vertically are widely used for nondirectional antennas on the surface of the Earth because they radiate equally in all horizontal directions, while the power radiated drops off with elevation angle so little radio energy is aimed into the sky or down toward the earth and wasted. Omnidirectional antennas are widely used for radio broadcasting antennas, and in mobile devices that use radio such as cell phones, walkie-talkies, Wifi, cordless phones, GPS as well as for base stations that communicate with mobile radios, such as police and taxi dispatchers and aircraft communications.

Antenna omnidirectional antenna typically has a 360-degree radiation pattern. Usually the polarization field E is vertical. Strengthening the omni antenna is usually very low about 3-12 dBi only. Usually used for the connection Point-To-MultiPoint (P2MP). Good enough for 1-5 km distances, especially if the directional antenna with high reinforcement in use on the client side.

Shown in the picture below is the radiation pattern of omnidirectional antenna 140 RFDG to 2.4GHz made by RF Linx (http://www.rflinx.com). Horizontal radiation pattern close to 360 degrees. Basically horizontal polarization radiation field-E. For comparison, the vertical radiation pattern is very thin pieces.

All this means that only stations that are in a 360-degree radiation will be examined by the omni antenna. This omni antenna can not provide service at the station located above the antenna.

Ref : 

http://en.wikipedia.org/wiki/Omnidirectional_antenna

http://opensource.telkomspeedy.com/wiki/index.php/Omni

Wireless USB

Wireless USB is a short-range, high-bandwidth wireless radio communication protocol created by the Wireless USB Promoter Group. Wireless USB is sometimes abbreviated as "WUSB", although the USB Implementers Forum discourages this practice and instead prefers to call the technology "Certified Wireless USB" to differentiate it from competitors. Wireless USB is based on the WiMedia Alliance's Ultra-WideBand (UWB) common radio platform, which is capable of sending 480 Mbit/s at distances up to 3 meters and 110 Mbit/s at up to 10 meters. It was designed to operate in the 3.1 to 10.6 GHz frequency range, although local regulatory policies may restrict the legal operating range for any given country.

Uses

Wireless USB is used in game controllers, printers, scanners, digital cameras, MP3 players, hard disks and flash drives. Kensington released a Wireless USB universal docking station in August, 2008. It is also suitable for transferring parallel video streams, while utilizing the Wireless USB over Ultra-widebandWB bandwidth.

Life

Wireless USB life will depend on the usage and environmental conditions. Proper usage will make the usb life long lasting. Improper disconnectivity of the Wireless usb leads to degrade the performance. Mounting and Unmounting procedures are very important in these adapters.

Wireless USB vs. 60 GHz

Few issues differentiate the two technologies:

Line of Sight: at 60 GHz, radio communication is blocked by any intervening object, which implies the need for open line of sight. Wireless USB is based on the UWB platform, which operates in the 3.1 to 10.6 GHz frequency range, and therefore intervening bodies can be passed through with no line-of-sight limitation.

Mobility: the 60 GHz technology is appealing to the wireless video market because it is supposed to deliver multi-gigabit-speed wireless communications. In order to support such heavy demands, the underlying MAC layer should be able to process this huge amount of data. For these requirements, the 60 GHz-based solutions will need higher power consumption, and bigger chips, which are less suitable for mobile units or devices.

Ref : http://en.wikipedia.org/wiki/Wireless_USB

Wajan Bolic

Antenna Saffron, or e-goen Wajanbolic is a breakthrough in technology RT / RW-net. Antenna Wajanbolic e-goen to be a client that cheap in a RT / RW-net so that we can air with cheap Internet. Internet cheap does not mean to steal bandwidth and the Internet was free, like most people think. Internet becomes cheaper because the cost burden on the responsibility of busy-busy by many to use in a neighborhood in the RT / RW-net

Gunadi and e-goen Wajanbolic

Antenna e-goen Wajanbolic developed by Mr. Gunadi (Pak Gun) or more known e-goen. Gun Pak comes from alumni STEMBAYO Jogyakarta. The latest information, he worked in Indosat to be one that is responsible in Indosat Earth Station in Purwakarta. From 2005-early 2006, the figure of the dominant e-goen inspire the nation of Indonesia to develop antennas & antenna pan frying in Indonesia. Antenna skillet that came to be known as e-goen Wajanbolic become the mainstay for those who want to build RT / RW-net or cheap wireless Internet at his house with a capital of about Rp. 300-350000 alone.

Mr. Gun active on the mailing list subscriber indowli@yahoogroups.com indowli@yahoogroups.com and teach techniques to make low-cost antennas using a skillet, cans, pipes pralon. With very simple equipment we can build a wireless Internet connection which is far enough to reach more areas of 2-4 km.

Ref : http://opensource.telkomspeedy.com/wiki/index.php/Wajanbolic

Hotspot (Wi-Fi)

A hotspot is a site that offers Internet access over a wireless local area network through the use of a router connected to a link to an Internet service provider. Hotspots typically use Wi-Fi technology.
Hotspots may be found in coffee shops and various other public establishments throughout much of the developed world.


History
Public access wireless local area networks (LANs) were first proposed by Henrik Sjödin at the NetWorld+Interop conference in The Moscone Center in San Francisco in August 1993. Stewart did not use the term hotspot but referred to publicly accessible wireless LANs. Stewart went on to found the companies PLANCOM in 1994 (for Public LAN Communications, which became MobileStar and then the HotSpot unit of T-Mobile USA) and Wayport in 1996.
The term HotSpot may have first been advanced by Nokia about five years after Stewart first proposed the concept.[citation needed]
During the dot-com period in 2000, dozens of companies had the notion that Wi-Fi could become the payphone for broadband. The original notion was that users would pay for broadband access at hotspots.
Both paid and free hotspots continue to grow. Wireless networks that cover entire cities, such as municipal broadband have mushroomed. Wi-Fi hotspots can be found in remote RV / Campground Parks across the US.
Many business models have emerged for hotspots. The final structure of the hotspot marketplace will ultimately have to consider the intellectual property rights of the early movers; portfolios of more than 1,000 allowed and pending patent claims are held by some of these parties.

UsesThe public can use a laptop, Wi-Fi phone, or other suitable portable device to access the wireless connection (usually Wi-Fi) provided. Of the estimated 150 million laptops, 14 million PDAs, and other emerging Wi-Fi devices sold per year for the last few years, most include the Wi-Fi feature.
For venues that have broadband Internet access, offering wireless access is as simple as purchasing one access point (AP), in conjunction with a router and connecting the AP to the Internet connection. A single wireless router combining these functions may suffice.

Locations
Hotspots are often found at restaurants, train stations, airports, military bases, libraries, hotels, hospitals, coffee shops, bookstores, fuel stations, department stores, supermarkets, RV parks and campgrounds, public pay phones, and other public places. Many universities and schools have wireless networks in their campus.

Reference : http://en.wikipedia.org/wiki/Hotspot_(Wi-Fi) 

RT / RW - Net

RT / RW-net product actually earned a lot of people in Indonesia who crave cheap Internet. In terms of policy RT / RW-net shows a lack phenomenon circumstances legal space for community-based infrastructure, which is built with homemade equipment, from the people, by the people, by the people. There is no legal space for infrastructure Wireless Internet using WiFi.

The existence of sophisticated information technology equipment is not enough. The success of RT / RW-net in Indonesia is due to process technology pemandaian community on the Internet the cheap alternative. Later today, the Wireless Internet technology seems to be the backbone of the RT / RW-net in Indonesia.

Details of technology RT / RW-net in the technology explained in RT / RW-net.

Reference : http://opensource.telkomspeedy.com/wiki/index.php/RT/RW-net