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Frequently Asked Questions

Highlights:
dBi versus dBm

RF Cable Questions
007GT TurboTenna WaveGuide Booster Questions
Buyer Questions about Speed, Range and Coverage
Questions related to Wireless Distribution System (WDS)


dBi versus dBm

dBm is an abbreviation for the power ratio in decibels (dB) of the measured power referenced to one milliwatt (mW). It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form.

Since it is referenced to the watt, it is an absolute unit, used when measuring absolute power. By comparison, the decibel (dB) is a dimensionless unit, used for quantifying the ratio between two values, such as signal-to-noise ratio (SNR).

dBi (isotropic) — the forward gain of an antenna compared with the hypothetical isotropic antenna, which uniformly distributes energy in all directions. Linear polarization of the EM field is assumed unless noted otherwise.

Zero dBm equals one milliwatt. A 3 dB increase represents roughly doubling the power, which means that 3 dBm equals roughly 2 mW. For a 3 dB decrease, the power is reduced by about one half, making −3 dBm equal to about 0.5 milliwatt.

For instanance, when a +12dBi antenna is driven by a +23dBm WiFi adapter the total absolute power output becomes 12dBi +23 dBm = 35dBm or 3,162mW.

If the dBm is expressed as a negative value, such as -54dBm, it means that the radio is receiving an absolute signal power of 0.000003981mW. Although the power looks pretty low, the Rx sensitivity of the WiFi adapter is high enough to treat it as a good signal strength.

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RF Cable Questions

I need to connect the TurboTenna 007GT to my desktop PC and occasionally to my notebook computers but they both have different RF connectors, could you get me a cable adapter?

There are two options that you can go after. Assuming that you have a 6FT LMR-195 (N-male to RP-SMA) RF cable connecting the TurboTenna 007GT to your desktop PC, you may either order a 6 inches LMR-100A (SMA to MC Card), or another 6FT LMR-100A (N-male to MC Card) RF cable for your notebook computer.

The cable attenuations are:

6FT LMR-195 RF cable = 1.1dB;

6FT cable with 6 inches adapter PLUS insertion loss = ~ 3.3dB;

6FT LMR-100A RF Cable = 2.3dB;

As you can see, a new 6FT cable for the notebook computer incurs less signal attenuation than using a cable adapter.

Is it possible to run a 27 feet cable to a 2.4GHz antenna? Will there be too much signal loss?

The predicted signal attenuation for LMR-100A is:

Length                3ft   6ft   9ft   12ft   15ft   18ft   21ft   24ft   27ft
Loss (dB)            1.2   2.3   3.5   4.7    5.8    7.0    8.2    9.3    10.5
Efficiency (%)     76.4 58.4  44.6  34.1  26.1  19.9  15.2   11.6   8.9

If you run a LMA-100A cable at 27ft with a TurboTenna 007GT, theoretically the NET gain is +12dB-8.9dB = 3.1dB ignoring the insertion losses of the connectors, and you'll get the deteriorated signal-to-noise ratio also. Hence running the cable at this length is not recommended. We offer 10ft max.

For LMR-195 @27ft, loss is 5dB at efficiency of 31.4%.

For LMR-400 @27ft, loss is 1.8dB at efficiency of 66.3%.

What are the attenuation and efficiency characteristics of the LMR-195 RF coaxial cable?

The predicted signal attenuation for LMR-195 is:

Length                3ft   6ft   9ft   12ft   15ft   18ft   21ft   24ft   27ft
Loss (dB)            0.6   1.1   1.7   2.2    2.8    3.3    3.9    4.5    5.0
Efficiency (%)     87.8 77.3  68.0  59.8  52.6  46.2  40.7   35.8   31.4

What are the attenuation and efficiency characteristics of the LMR-400 RF coaxial cable?

The predicted signal attenuation for LMR-400 is:

Length                3ft   6ft   9ft   12ft   15ft   18ft   21ft   24ft   27ft
Loss (dB)            0.2   0.4   0.6   0.8    1.0    1.2    1.4    1.6    1.8
Efficiency (%)     95.5  91.3 87.2  83.3  79.6  76.0  72.6   69.4   66.3

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007GT TurboTenna WaveGuide Booster Questions

What is a TurboTenna 007GT Booster?

danets and its team have optimized every aspect of the sophisticated wave guide design and turned it into the TurboTenna 007GT Booster for wireless LAN range extension and coverage, delivering a remarkable 12dBi of gain, compared to ratings of as little as 2dBi for the antennas built into most Access Points.

What is the difference between an indoor and an outdoor antenna?

An outdoor antenna must be equipped with lightning protection, and it is designed to work in an atmospheric environmental condition. An indoor antenna is designed to provide coverage within the premises.

How do I connect the TurboTenna 007GT Booster to the access point or wireless client adapter card?

The 2.4GHz RF cables are not the same as the TV coaxial cables that you find at the hardware store. We use USA made LMR-100A high frequency coaxial cable which operates at 2.4GHz with minimum signal loss. The RF cable connects to the TurboTenna 007GT using the N-male connector and to your access point using a matching RF connector. The TurboTenna 007GT is a wireless signal booster. Typically what you have to do is to unscrew the detachable antenna (unscrew one if there are two) from your access point, connect one end of the RF cable to it with the matching RF connector and the other end to the TurboTenna 007GT using the N-male connector. Depending on the model of your access point, the matching RF connector may vary but typically it could be MC Card, RP-SMA or RP-TNC type. See RF cable for more info.

My router has two antennas. Where do I attach the TurboTenna 007GT Booster?

If your router or access point has removable antennas, unscrew one of the antennas and connect the TurboTenna 007GT Booster with the optional Pigtail. We recommend using the side that points away from a wall or obstruction. You can keep the other antenna attached, but also try operating without it as it may cause interference (fake). If your device has an external antenna jack, connect the Pigtail directly to it, and leave the other antennas in place.

How do I measure the signal strength of the TurboTenna 007GT Booster?

Windows XP users can use the built-in Wireless Network Connection Status window, or consult danets for further information.

What kind of cable do I use to hook up to the TurboTenna 007GT Booster?

The TurboTenna 007GT Booster has an N-female socket. You can purchase the optional Pigtail (RF cable) that attaches to the socket. The other end of the Pigtail connects to your wireless device.

I want to mount my TurboTenna 007GT Booster about 25 feet away from my access point. can you provide me with a 25 feet long Pigtail?

In general, the longer a Pigtail is, the more of a signal loss you may experience. For that reason, we currently limit production of our cables to 10 feet. 25 feet would cause a severe signal loss. You could purchase a wireless bridge, such as the Linksys WET54G or Buffalo WBR2-G54C, which attaches to your Ethernet port. A 25 feet long Ethernet cable could then be used without substantial signal loss.

I have a Macintosh. What are my options?

Linksys, D-Link, Buffalo and Belkin have access points and PC cards available. Just make sure that they have an external antenna jack to attach a TurboTenna 007GT Booster. If you have a new Mac, Apple's new Airport Extreme (modem edition only) uses a new type of connector for which we also have engineered a Pigtail.

Can I return the TurboTenna 007GT Booster if I don't pick up a signal?

Yes, you may return the TurboTenna 007GT Booster, however, you are responsible for all shipping and handling costs. The TurboTenna 007GT Booster must be returned in its original condition and in its original package within 7 days of purchase for replacement.

Is it legal to use the TurboTenna 007GT Booster?

Yes, our TurboTenna 007GT Booster and Pigtails have been tested and comply with part 15 of the FCC rules. Make sure other wireless devices that you use also comply. Compliance with FCC regulations is your responsibility. Check with your Internet Service Providers to find out if they permit sharing of their Internet connections.

How safe is it to use a TurboTenna 007GT Booster?

The TurboTenna 007GT Booster should not be used outdoors without being properly grounded. A connection for a ground cable is provided with each TurboTenna 007GT Booster. Other than that, it is subject to the same radio waves as your cordless phone, microwave, cell phone, radio, etc. If you are concerned about your sensitive data, as with any other wired connection, without using encryption your network can be subject to potential eavesdropping. Always take appropriate security measures to protect your data.

Can I mount the TurboTenna 007GT Booster?

Each TurboTenna 007GT Booster comes with a mounting socket for standard tripod units. This socket can be removed so that you can use your own mounting hardware.

Can I mount the TurboTenna 007GT Booster outside?

Yes, the TurboTenna 007GT Booster is weather resistant. Make sure that you ground it properly.

Can I use a TurboTenna 007GT Booster to access online games with my Playstation? What about my Pocket PC?

You can user your TurboTenna 007GT Booster with any wireless network (802.11b/g) enabled device, provided it has an external antenna or an Ethernet port. To use your Playstation in the Starbucks parking lot, you can get a new wireless Ethernet bridge from Linksys.

Is the TurboTenna 007GT Booster guaranteed?

All TurboTenna 007GT parts are guaranteed. danets makes no guarantee of actual performance as several factors may inhibit the TurboTenna 007GT Booster effectiveness, such as obstructions, atmospheric conditions, distance, and strength of the originating signal. In case of defect, the TurboTenna 007GT Booster must be returned in its original condition and in its original package within 7 days of purchase for replacement.

Can I connect the TurboTenna 007GT to the ASUS a8v-E Deluxe motherboard?

Yes, the Asus a8v-E Deluxe motherboard has an onboard 802.11b/g adapter equipped with an external WiFi antenna port which is able to connect and work with the TurboTenna 007GT using a 6ft LMR-100A RF cable.

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Buyer Questions about Speed, Range and Coverage

My 802.11g can go up to a speed of 54Mbps, why do I always get much below that?

Signal strength and quality affect the connection speed. You'll get a slower speed if you are far away from your access point, or if walls are blocking the line-of-sight. In such a situation, you'll need an antenna such as the TurboTenna 007GT Booster to improve the wireless coverage. 

I am losing signal strength in parts of my house, particularly to a room at a remote corner. Can a TurboTenna 007GT Booster bridge the gap and how can I maximize its effect?

Yes, the TurboTenna 007GT Booster may help to boost the signal depending on the layout of your house, and the obstruction that is weakening the signal. Signal strength decreases as the distance between the access point and your computer increases. Try moving your access point and TurboTenna 007GT Booster in different directions, even away from the area that you are trying to reach. Sometimes rotating the TurboTenna 007GT Booster on its axis so that the connection point sideways or up will help to boost the signal. Finally, in your remote room try moving your laptop toward the middle of the room, away from the walls or metal. You can also try tilting your laptop (or WiFi receiver if you have a desktop computer) on its horizontal axis.

I do not have an access point or Internet connection, but I was told that my apartment complex has a WiFi network. Can I get free Internet access with the TurboTenna 007GT Booster?

You will need a 802.11b or 802.11g wireless device that connects to your laptop or desktop computer. There are few 802.11b/g PCMCIA wireless adapter in the market today equipped with and external RF antenna port, such as the newly launched Buffalo WLI-CB-G54S at 125*/54 Mbps High Speed Mode. Normally the build-in antenna would barely pickup any signal next door at all, that is why you need your wireless adapter to be able to connect to the TurboTenna 007GT Booster which scans and picks up the signal(s) at the far end.

Whether or not you will be able to pick up a signal depends on the proximity of a broadcasting signal, obstructions, and signal strength. If the person who broadcasts the signal uses encryption and MAC address screening, you have to request a username and password or submit the MAC address of your wireless adapter to gain access.

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Questions related to Wireless Distributed System (WDS)

Can Buffalo's Bridge Access Points repeat to third-party vendors Bridge Access Points?

A. When the 802.11b/g standards were ratified, they did not include any standards for bridging and repeating. This aspect of wireless networking was left up to manufacturers to implement as they saw fit. Because of this, there is very little compatibility between different vendors' products as far as bridging/repeating. For this reason, we can only guarantee and support bridging/repeating with other Buffalo Products.

How do I configure the AirStation to support VPN pass-through?

In the AirStation configuration screen, click Advanced Settings => Network setting => Address Translation,

1. Select NAT table settings, click the Manual radio button under Protocol (WAN). Enter 47 in the Protocol number field.Select Manual setting under IP Address of LAN and enter the destination LAN side IP address in the Manual setting field. Click Add to NAT table.

2. Select NAT table settings, click the TCP/UDP radio button under Protocol (WAN). Select Manual setting of TCP port.. Enter 1723 in the Port number field.Select Manual setting of TCP port under IP Address of LAN and enter the destination LAN side IP address in the Manual setting field. Click Add to NAT table.

Are the AirStation 54Mbps products compatible with Apple Macintosh Computers?

Yes. On 6-19-2003, Apple released Airport Software version 3.1 for OS 10.2.6.

This update provided support for third-party 54Mbps 802.11g client adapters using the Broadcom chipset.

Buffalo U.S.A. provides support for the AirStation 54Mbps Notebook Adapter (WLI-CB-G54A) and AirStation 54Mbps Desktop PCI Adapter (WLI-PCI-G54) with this update. Appletalk is supported.

The AirStation 54Mbps Notebook Adapter (WLI-CB-G54A) is compatible with Apple Powerbooks with an available CardBus slot.

The AirStation 54Mbps Desktop PCI Adapter (WLI-PCI-G54) is compatible with Apple G3 or G4 Tower computers with an available PCI slot.

The AirStation 54Mbps Wireless Router (WBR2-G54, WBR2-G54S and WHR3-G54) and AirStation 54Mbps Wireless Bridge (WLA-G54, WLA-G54C) are configured via a web browser and are supported with Macintosh as well.

OS 10.2.6 is required. iBooks and iMacs are not supported.

The AirStation 54Mbps CardBus Card (WLI-CB-G54/WLI-CB-G54S) is not supported.

What are the common WDS (Wireless Distribution Systems) troubleshooting?

* NOTE: The most common issue with WDS installations is using the wrong MAC address. The proper MAC Address for the access points is the ‘Wireless MAC Address’. The best place to document this is under the ‘System Information’ section of the configuration web page. For proper setup, please continue reading this document. **

Problem:
Communication problems with WDS (wireless bridging/repeating).

Cause:
WDS is a very complex bridging system, and it is not part of the 802.11b or 802.11g standard.

Restrictions:
Please verify that the following conditions are met (if just one condition is not satisfied, then WDS cannot be used on the wireless network):

1. All wireless access points in the wireless bridge need to be from the same vendor (e.g. all Buffalo access points).

(NOTE: At time of publication, the Apple Airport Extreme WILL work in WDS with Buffalo G54 access points.)

2. No single access point can communicate with more then six other access points in the wireless bridge.Good Practices:

The following is a list of good practices with WDS:

1. Start the wireless bridge system with only two access points and then add more access points.

2. Setup all access points in the wireless bridge in close proximity before they are deployed to their proper location.

3. Only one access point in the wireless bridge should be serving DHCP and routing services unless a routed wired network exists.

Proper Setup:
Please follow the following steps to properly setup WDS.

1. It is recommended that all access points in the bridge are reset to their factory default settings. This is done by holding the INIT button on the rear of the access point down for 5-10 seconds.

2. Login to the first access point in the wireless bridge (this should be the DHCP server enabled access point if there is not already a routed wired network).

3. Click on the ‘Advanced’ button.

4. The wireless settings page will appear. Select the proper settings for the wireless network. Record all settings on a piece of paper. All settings except for the ESS-ID need to be identical amongst all access points in the bridge.

(NOTE: If roaming is desired, then make sure the ESS-ID settings need to be identical as well). Press the ‘Set’ button if any changes are made.

(NOTE: If the IP address was changed, then reconnecting to the access point for configuration will require accessing it via its new IP address in a web browser (e.g. http://NEW_IP_ADDRESS).

5. Click on the ‘LAN port’ link on the left.

6. Check that the ‘LAN side IP address’ values are correct for your network, or leave them as default. Record the ‘LAN side IP address’. Press the ‘Set’ button if any settings on this page have been set.

7. Click on the ‘Management’ link on the left.

8. The System Information page will appear. In the Wireless section of the table record the MAC address (including the :’s). Please make sure the MAC address is recorded from the Wireless section and not the other sections.

9. Logout of the access point by clicking on the ‘Logout’ link on the left. Close the browser window.

10. Login to the second access point in the wireless bridge.

11. Click on the ‘Advanced’ button.

12. The wireless settings page will appear. Select the proper settings for the wireless network. Refer to the settings recorded from the first access point. All settings except for the ESS-ID need to be identical amongst all access points in the bridge.

(NOTE: If roaming is desired, then make sure the ESS-ID settings need to be identical as well).

13. Click on the ‘LAN port’ link on the left.

14. Make sure that the ‘LAN side IP address’ ‘IP address’ setting is different then the first access point. The IP addresses cannot be the same, but they should be on the same network. It is recommended that the IP address of the second access point is one higher then that of the first access point. Thus, if access point one’s address is 1.1.1.1, then access point two’s address should be 1.1.1.2. If there is a ‘DHCP server function’ setting on this page, then make sure to set it to ‘Do not use’ or to ‘Disabled’. Press the ‘Set’ button when finished.

(NOTE: If the IP address was changed, then reconnecting to the access point for configuration will require accessing it via its new IP address in a web browser (e.g. http://NEW_IP_ADDRESS).

15. Click on the ‘Wireless bridge (WDS)’ link on the left.

16. Enable the WDS function and press the ‘Set’ button.

17. Enter the Wireless MAC Address of the first access point (which was recorded on Step 8) into the field that say ‘MAC Address of AirStation(Wireless)’ (include the :’s). Press the ‘Add’ button.

18. The Wireless MAC address inputted on the step above will appear in the ‘Connected AirStation’ table. Please check that the checkbox under enable is checked, and then press the ‘Enable marked item’ button.

19. At the top of the page, press the ‘Apply’ button.

20. Once the router has rebooted, click on the ‘Management’ tab on the left.

21. The System Information page will appear. In the Wireless section of the table record the MAC address (including the :’s). Please make sure the MAC address is recorded from the Wireless section and not the other sections.

22. Logout of the access point by clicking on the ‘Logout’ link on the left. Close the browser window.

23. Login to access point one again.

24. Click on the ‘Advanced’ button.

25. Click on the ‘Wireless bridge (WDS)’ link on the left.

26. Enable the WDS function and press the ‘Set’ button.

27. Enter the Wireless MAC Address of the first access point (which was recorded on Step 21) into the field that say ‘MAC Address of AirStation(Wireless)’ (include the :’s). Press the ‘Add’ button.

28. The Wireless MAC address inputted on the step above will appear in the ‘Connected AirStation' table. Please check that the checkbox under enable is checked, and then press the ‘Enable marked item’ button.

29. At the top of the page, press the ‘Apply’ button.

30. Once the router has rebooted, click on the ‘Management’ tab on the left.

31. Click on the ‘PING test’ link on the left.

32. In the ‘Destination’ field enter the IP address of the second access point and press the ‘OK’ button.
 
a. If the ‘Result’ section of the table reports information like, “1st: 64 bytes from IP_ADDRESS” then the WDS bridge is effectively working.
 
b. If the ‘Result’ section of the table reports “Destination Host Unreachable”, then an error has occurred during the setup.

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