VisiWave Blog

After a very long time coming, version 2.0 of VisiWave Site Survey was finally released today. We had a successful beta program running for the last month and are very happy with the end results. Hopefully you will be too. See below for a list of new features in this release.

If you purchased a license to VisiWave after July 1, 2008, you will automatically receive a free upgrade. We will email you new registration codes shortly. If you don't receive these codes, just email us for more information.

All other current customers can upgrade to version 2.0 for a small fee. Just click on the Purchase link on our website and scroll down to the bottom. Add the "Update to Version 2.0" to your cart and proceed with your checkout. Once your existing license has been verified, you will receive new registration codes.

Those that installed the beta of version 2.0 will need to act before Sept 30 by either upgrading or re-installing your licensed version.

If you aren't sure if you want to upgrade, go ahead and install the trial version of 2.0 over-top of your current release. If you like it, then upgrade. If you wish to stick with your current version, then just re-install that version over-top of version 2.0 and continue to use it.

NEW IN THIS RELEASE

o Record Noise Levels & SNR with Wi-Spy

VisiWave now uses a Wi-Spy device--if present--to get the background noise every time a Wi-Fi data point is collected. VisiWave then uses the noise level to create real Signal-to-Noise Ratio (SNR) and noise level graphs. Just make sure your Wi-Spy is plugged in while collecting Wi-Fi data. VisiWave will then automatically record noise levels as well as signal strengths for each collected data point.

o View Detailed Data on Each Collected Data Point

Full information about every data point collected can now be immediately viewed from within the data collection application. You can view all the access points seen at each location, their signal strengths, MAC addresses, SSIDs, etc. Plus you can view all the interference data collected using the Wi-Spy spectrum analyzer.

o Visualize Coverage using Google Earth Viewer

Creating reports in Google Earth is now an official feature of the product (previously, it was only available as a beta feature). During the beta period, customers have proven how truly useful and solid this feature is for fully understanding their wireless coverage. NOTE: The current beta version (4.3.7284) of the free Google Earth viewer has a bug that prevents the information balloons from displaying in the right location. To work around this until Google fixes it, turn off the Terrain view under the Layers section on the left panel.

o Set Scale Interactively

VisiWave needs to know the scale of the image you use as your survey map. For example, a pixel on the map might equal two feet. This can now be done set or updated using an interface provided by VisiWave. You can click on the map in two places and tell the software the distance and it will calculate the scale for you.

o Garmin USB GPS Device Support

In addition to serial GPS devices, VisiWave now natively supports Garmin GPS devices that connect to your laptop using USB.

o Estimate Access Point Locations Based on Coverage

A Google Earth report can now show you on the map where every access point is located. The locations are estimates based on the signal data collected.

o Automatic Checks for Updated Versions

VisiWave now checks for a new release of itself and installs the new release if requested. You can have it check daily, weekly, monthly, or only when you ask it to check.

o GPS Location and Status Displayed on Status Bar

If you have set the GPS location for your survey map, then the current latitude and longitude is now shown on the status bar while collecting data. Also, the status of the GPS device is displayed while collecting data using the GPS device.

Some site surveys are done after the access points have been installed and are operating. Sometimes you need to do a site survey on a new building that does not have any access points. VisiWave can handle either type of survey. Here we'll go over the latter case: a pre-deployment site survey.

We strongly believe that you need to actually measure radio waves in the field to get a realistic picture of your wireless coverage. We recommend using a temporary access point during a pre-deployment site survey. VisiWave makes this quick and easy.

To begin, place a temporary AP (it doesn't have to be connected to the network, just powered up), collect survey samples, and save the results in a survey file. Then move the temporary AP, collect more samples, and save the results in a different survey file. Repeat this process until the entire area is covered. When creating a report, you can then merge the survey files together into one large survey file using the Merge Survey Files menu item found in the Reporting application. By selecting the "Force APs to be unique" option, your one temporary AP will look like many individual APs when you create coverage graphs. VisiWave treats each AP location as a unique AP in the reporting results. Look up "Merge Survey Files" in the supplied User Guide for more information.

Using this method, you can view each AP's coverage and get an overall view of your wireless network. Also, taking actual measurements allows you to view any overlapping coverage provided by external access points. This will show you what areas contend with neighboring access points and what channels those APs are using.

In general, VisiWave supports GPS devices that adhere to the NMEA standard and that connect to your computer over a serial port. However, many popular USB GPS devices have extra software that makes the device present itself as a regular COM port.

Some that are known to work: Garmin eTrex line or their USB 18 device with the Spanner software. Magellan's devices also work well.

You will need to go to the Options menu item in the data collection application. Set the GPS port to whichever serial port your Garmin is connected to (or just try each of the listed ones until it works).

To collect data using VisiWave and a GPS:

1. Make sure your GPS is attached and is locked onto enough satellites for a good signal.

2. In VisiWave, go to the Options menu and set the GPS port to the COM port that your GPS device is connected to. If you aren't sure, just try each listed COM port until one works.

3. Make sure VisiWave's Capture Mode is set to GPS (look under the Survey menu under Capture Mode).

4. Press the Start Collecting button.

5. If this is the first time using GPS for this survey, you'll get a message to set the initial latitude/longitude of your survey map. Press OK and then click on the map where you are currently standing.

6. You are now collecting survey data. Drive/walk around.

You should see a blue circle on the map where you currently are. Look in the status bar (at the bottom of the window). The 3rd pane from the right should have a number in it. This is the count of data points collected so far. This number should be increasing by about 1 every second or so.

As you move, the blue circle should move with you and a line should appear. Also, the data point count should keep increasing. When you are done collecting data, press Stop.

We also have a tutorial of this on our website. From our homepage, click on Tutorials on the left. Then click on "Demo 1: Collecting Survey Data using GPS".

As always, you can email us if you still can't get this working.

802.11n support is present right now in VisiWave for the draft implementations. VisiWave doesn't record any 802.11n-specific data (such as whether channel bonding is in use and which extra channel is used), but the primary channel, signal strength, and maximum data rate for 802.11n is recorded--just like it is for 802.11a/b/g. This produces the same rich views of your wireless coverage that you've come to expect from VisiWave for 802.11n networks as well.

This support is available in the shipping product today. Most 802.11n (draft) wireless adapters are already supported by VisiWave. To make sure your's is, download our CheckAdapter program to test your adapter.

To start with, here are some discussions about how VisiWave creates it's heat maps.

VisiWave interpolates what it thinks is the coverage in areas where you didn't collect data. This is just a guess and it is best to actually collect data there, but VisiWave does a decent job estimating coverage in these areas based on what it knows.

When creating the coverage graphs, VisiWave needs to divide the survey area up into cells. It then takes the data points you collected and assigns coverage values to each cell.

If VisiWave could depend on you to collect data in a regular pattern throughout the entire survey area, it wouldn't need to form these cells. But that is an unrealistic expectation so the cells are necessary and effective for real-world data collection.

So how big are the cells? Assume your survey area is roughly square. Then each cell takes up about 1% of the area. So an area 100m by 100m would have a cell 1m by 1m. If your survey area is twice as wide as it is deep, then the cell size would be about 1% of the width and 2% of the depth. For example, an area 200m wide by 100m deep would have a cell size of 2m wide by 2m deep.

So as a general rule, you should collect a data point about every 1% to 2% of the total width/height of your space. So in a space that's 500m by 500m you should take a reading about every five to ten meters in each direction. More frequently is fine and may produce more detailed maps. As stated above, you usually aren't able to collect data in a perfect grid so the software fills in where you don't collect data.

It should also be pointed out that the level of detail you set for the graph comes into play. The above discussion assumes you have chosen the highest level of detail. If you lower the detail level, then you also lower the number of cells (making each cell larger). In general, setting the detail level to half will roughly double the size of each cell which means you can collect data that is even further apart.

To completely simplify the above, if you are surveying a decent sized building, you want to collect data at least every 5 to 10 feet (2 to 3 meters). If you are surveying a downtown area, you might want to collect data more like every 25 to 50 feet (10 to 20 meters)--or better.

We are often asked what is the difference between the Pro version and the SO version and which version is right for me.

The only difference between the Pro version and the Software Only ("SO") version is that the Pro version comes with the navigation unit. Both are equally accurate in creating coverage graphs (as long as you collect a similar set of data). It can be easier to collect survey data using the Pro version, but using the Continuous capture mode in the SO version can capture just as much survey data and just as accurately--just be sure to walk at a constant pace between clicks and to not linger at one location while clicking on the floor plan.

We usually recommend the Pro version for someone that will be doing regular (frequent) site surveys, usually in locations where they aren't very familiar with the building layout. And the SO version for everyone else. If you aren't familiar with the survey area, the Pro version automatically tells you where you are and which way you are heading. This can be handy when surveying deep in the interior hallways of an unfamiliar building.

Note that both versions support GPS so if you are only doing outdoor surveys, then the SO version makes the most sense.

Google Earth integration is very easy as long as you know how to set the latitude/longitude position of your survey area map.


The first place to start when trying to use Google Earth with VisiWave is our online tutorials. They cover all the steps necessary to collect data and create a Google Earth export file. Click on the Tutorials link on our homepage. Start by viewing Demo 3: Collecting Survey Data. Then view the two tutorials on collecting survey data and viewing it using Google Earth. The tutorial Demo 2a: Using Google Earth with VisiWave shows how to use Google Earth with a VisiWave coverage graph.

Some other tips:

• Make sure that when you collect data, the top of your survey area map points north.


• Make sure your Scale is set accurately (otherwise the overlaid graphs won't line up with the Earth's surface).


• If you aren't using a GPS, you'll still need to set the latitude/longitude of your map. You can use Google Earth to get the lat/long position of a place on your map and then enter that in VisiWave (see the tutorial).


• If you are doing a large survey and then try to export everything to Google Earth, the resulting KML file might be so large that it is cumbersome to use. On large surveys, you should split the export up into smaller sections: possibly including a subset of access points (using the "APs to Include" parameter), including the spectrum data in a separate file, or including just data combined by SSID (instead of including data on each individual access point).


• When viewing the export window, press F1 or click on Help to view detailed information on each parameter.

The first thing to check is that you installed the Serial-to-USB driver that comes on the small CD along with the USB-to-Serial conversion cable. Nothing will work without first installing the appropriate drivers. Windows should prompt you for this CD when you first connect the converter cable.

Next, make sure you have selected the correct COM port for your serial device. Under VisiWave, select the Option menu item under the File menu. Select the correct COM port next to "Nav Unit Serial Port".

To find out which COM port is the correct one, go to Windows' Control Panel. Double click on System. Click on the Hardware tab. Then click on the Device Manager button. Scroll down until you see "Ports (COM & LPT)". Click the plus next to this item. You should see an entry that starts "Prolific USB-to-Serial Bridge" followed by a COM port. That is the correct port number. If you don't see this entry, then the driver was probably not installed.

The navigation unit should now be usable by VisiWave. If you continue to have problems, as always, just send an email to support and we would be more than happy to help you.

We are often asked if we accept Purchase Orders when buying VisiWave. In general we do, but we reserve the right to not accept a PO.

To place an order using a PO, click on the Purchase link on our website. Select what you wish to purchase and proceed with the checkout as normal. For Payment Method, select "Check". On the last page of the checkout, enter the PO # in the Special Instructions box. Then fax or email us a copy of the Purchase Order (see the Contact Us page for details). Once the PO is verified and accepted, we'll ship the product.

Should you select "All" or "Only Strongest in each Cell" for the Data Points Included option on a 2D contour graph? And does this have anything to do with what you select under the "APs to Include" parameter?

When creating a 2D Contour graph, the survey area is split up into many small cells. Each cell potentially contains several different collected data points. Using this option, you can either use all data points found in the cell to determine the overall value of the cell, or you can specify that you only want the data points that come from the access point with the strongest signal to determine the overall cell value. Selecting "Only Strongest AP in each Cell" tells the product to sort through all the data points found in the cell and only examine the points that come from the access point with the strongest average signal level. The other data points are simply ignored.

Regardless of which setting you select, only the APs you selected in the APs to Include parameter are examined. Typically you would want to select "Only Strongest AP in each Cell". This simulates what coverage a laptop would see. The laptop would usually look at the AP with the strongest signal at its current location and ignore the others.

If you are just starting out with VisiWave Site Survey, the best place to look for help is to view one of our online tutorials. Each lasts just a few minutes, but they show you the most important features of the product.

You probably want to start with the "Collecting Survey Data" tutorial. It goes over loading a survey map, setting the scale, collecting survey data using two common methods, and exporting graph data to Google Earth.

You will also want to look through our Quick Start Guide. This short guide goes over collecting survey data and creating reports.

You can also always read the manual. It is installed as part of the product (even with the eval version). Just go to the Start menu, click on All Programs and then on VisiWave Site Survey. You'll see a link labeled User's Guide. This brings up the guide in your PDF viewer.

VisiWave also has a lot of help built into the application. Just press F1 or select help from the Help menu. Most every feature, button, and field in the program is explained in the built-in help system.

Of course, you can always email us for help as well. We do our best to give you thorough and timely answers to all support emails.

This blog exists to allow the VisiWave development team to share information with its current and future customers. You may find tips on how to use VisiWave, help with purchases, further explanation on new or existing features, tips on performing wireless site surveys, product announcements, or pretty much anything else we have to say.

Don't expect daily updates, but as we become aware of useful or important information, we'll type up a few words here to share that with you and the world.