Using a GPS to perform a Wi-Fi survey

It is important to perform a wi-fi survey so that you can determine not only the perfect place to locate your access point or bridge but to gain an understanding of the channel co-existence challenge you may face.  With wireless access points in surrounding neighborhoods and businesses, you will need to  perform a survey by walking around and mapping out the BSAs (Basic Service Area) of wireless that surrounds you and your organization.

Below is an example of our school’s perimeter.  Matt, Chris and James, students in the Computer Information Technology, class performed a survey using a Microsoft GPS and Vistumbler.  This survey revealed access points and their channels of current wireless at our institution and  includes APs in surrounding businesses and neighborhoods.  These were mapped using Google Earth after exporting their KML file from Vistumbler.

This type of survey allows IT professionals to analyze data exported to ensure the correct channels can be used at their organization.

Miller Goodroe Felts

After exporting the wireless information, you can analyze each access point or wireless device by clicking on it.  Below is an example of the information exported into Google Earth.   Each device shows SSID, Network Type, Mac Address, Channel, Security, Encryption Type, Data Rates, Latitude, Longitude and Manufacturer information.   Analyst using this information can also determine the best placement of wireless devices along with channel information.

ESSID Expanded

Channel co-existence is when access points share channels that are very close to one another.

802.11 wireless on 2.4 Ghz has three non-overlapping channels.  These channels are 1, 6 and 11.  The closer channels are, the more likely interference will take place.  With the amount of wi-fi in use today, IT professionals have to chose between 2.4 Ghz and 5 Ghz and and try to select channels that are not in use if possible.   Professional access points and bridges can also adjust power as necessary.   A dense population can make this very challenging.

If you look at the students’ survey by zooming out to see how many access points can be seen, this is what you are looking at!  Now you can see why site surveys are important at your organization.

Exploded

In addition to this survey, a secondary survey using a spectrum analyzer is very important to search for interference from other sources.  (See our review of the Airview Spectrum Analyzer)

analyzer-software

Channel information (Chart from Wikipedia)

NonOverlappingChannels2.4GHzWLAN-en.svg

Here’s another look at a wireless survey showing vertical lines and signal strength.  (James M. KML survey)

Another view James Miller KML

Windows 10 Tech Preview

I’ve been working on computers for a long long time.  It does seem that Microsoft gets it right, wrong and then right when they release operating systems.

When Windows 8 came out, we did find it was a good operating system but hard to navigate.   Users eventually became use to it and they eventually found hidden items..   Consumers of traditional Windows XP and Windows 7 will have no problem navigating Windows 10 if Microsoft keeps this release.  

The download for the preview  of Windows 10 can be found here.  It’s around 4 Gb and goes on smooth.  We’ll find out over the upcoming weeks if users begin having problems and what problems are being reported.  Now before you download it, be sure to read the rules about what to install it on and Microsoft’s recommendations.  It truly is for people who know the following – http://windows.microsoft.com/en-us/windows/preview-faq#faq=tab0

If you are going to participate in the Technical Preview, go over and look in the forum.  Hopefully Microsoft will assign a committee to stay in the forum, listen and communicate to engineers.  The forum is located here:

http://answers.microsoft.com/en-us/windows/forum/windows_tp?auth=1

I do want to note that I am already seeing people loading their computers with this OS.  You have to remember it will be polished up, improved and tweaked over the upcoming months.  Because there are thousands of programs and applications on ever type, model and make of computer with every type of hardware imaginable, there will be tons of updates coming.   There will be errors.   Consumers and technicians will report back and Microsoft will require this feedback.

Can you imagine writing an operating system for almost every piece of hardware on the market with every type of configuration?   With thousands and thousands of applications?

Loading Windows 10 Technical Preview

I of course loaded it in a  virtual computer and later on an older computer.  Both installations went smooth and was fast.  The setup is almost like Windows 8, 8.1 or 8.1 Update.   It really did appear to be smooth and was truly error free.

The setup on VMWare Player was like any other iso installation. (www.vmware.com)

Note:  Don’t download this to a production or home computer just yet, it is being reviewed.  

Upon signing in, the menu was back and enhanced with the Microsoft Store Apps.   The menu is now how it should have been.  Navigation was the same through windows, menus were the same in explorer and there was no more worrying about corners or apps that were running or the mysterious Charms Bar.  

While we will find hidden options and features later, one of the best features is multiple desktops for productive people who like multi-tasking.   I have to note that Linux has had this feature for many years and Microsoft has put this feature in.

Note: There will be those who pick it apart along with those who will find security holes in this operating system.    Of course today with viruses and vulnerabilities found in everything, we have entered a time that the business that patches their system quickly and thoroughly will win over the IT personnel in the world.   Also companies that make the easiest to use interface that works for home users that is affordable and has tons of freeware will also win out the consumer. 

Initial setup of VMware Player with 2GB of RAM, 2 Processors and only 30 GB of HDD space.

1 VMWare 1aVMWare

The initial boot up showed a familiar setup screen along with a minimum number of screens requiring any input.2loading 3main 4 agreement 5 disk space 6 installing 7 restart 8 Settings 9 internet

I did click setup a new account and on the next screen I elected to login locally.  10 account 11 apps

The ever familiar desktop found in Windows 8 loaded after signing in.  What I noticed first was the logo in the lower left corner produced a menu that should have always been there and no charms bar if I moved my mouse to the right side of the screen.12 Desktop 13 Finally a menu

Working with networks and group policies in the enterprise, I tested the network for speed and accuracy and dove into the group policy editor.   The network was very quick and responsive and it appears very little has changed in group policies.

14 Faster Than before  17 Computer info 17 Control Panel 16 Work Folder18 File manager

Searches for files or computers using a UNC path were exceptionally fast.19 unc path

Clicking the task view on the taskbar produced an Add a desktop option for anyone wanting to multitask.20 Task View Add a desktop

Clicking the Task View icon again (below) showed the active desktops.21 Extra Desktop

Opeing Apps on the menu gave an option to close them or minimize them using standard controls (below).  The right side of the App listed more options to control the app.22 App Controls

While I have had this installed for only an hour or so, I’m sure I’ll find some hidden features that will benefit users.  Now if Microsoft will keep the code trim, secure and keep controls where users can easily find them, they’ll have a hit.   There will also be a question if Microsoft will give the OS free to end users who own Windows 8 or 8.1 and if they will listen to end users from this point forward.

Network Switches – Avoid Daisy-Chains

When you are networking computers, wireless access points, printers and other nodes in multiple rooms, try to avoid daisy-chaining switches or using small 4-8 port switches when you are in a hurry.  Replace any hubs on your network as soon as you can.

With a hub, collisions can be >20% and utilization can stand at >50%.   By replacing a hub alone, you can reduce collisions to 5% on switches in rooms and <1% in the server room.  Switches help to isolate traffic, relieve congestion, separate collision domains (reduce collisions), segment and restart distance/repeater rules.

Daisy Chaining Switches -what not to do

Real world scenarios may require you to temporarily daisy chain switches.  If you do, test the network and run additional backbones or replace core switches to accommodate more nodes as soon as you can. (remember, replace any hubs in your network)

Daisy chaining

One of many solutions is to run independent lines to the core switch

alternative

Basic tips on optimization of your network -

  • Use stackable managed switches
  • Purchase switches that support
    IEEE 802.1D , IEEE 802.1p , IEEE 802.1Q , IEEE 802.1s , IEEE 802.1w , IEEE 802.1x , IEEE 802.3 , IEEE 802.3ab , IEEE 802.3ad (LACP) ,
    IEEE 802.3ae , IEEE 802.3u , IEEE 802.3x , IEEE 802.3z
  • Use a battery backup on the switches

This is the very basics behind network switch infrastructure.  Managing switches and using the IEEE standards above along with optimizing your network and managing the network infrastructure is important.

Excellent articles on Networking Infrastructure

http://www.lantronix.com/resources/net-tutor-switching.html

http://www.techrepublic.com/blog/it-consultant/only-novices-daisy-chain-switches/

Best Free Wi-Fi Tools

One of the best wi-fi tools you have on your Windows based computer is netsh.   Netsh can be used to find out information about wi-fi.

Open a command prompt and you can use these tools…

netsh wlan show networks

Netsh One

netsh wlan show networks mode=bssid

Netsh Two

inSSIDer

- Uses your current wireless card and connection software
– Works with Windows XP, Vista and 7 (32 and 64 bit)
– Compatible with most GPS devices
– Track the strength of received signals in dBm over time
– Sort by MAC address, SSID, Channel, RSSI, and Time
– Export Wi-Fi and GPS data to a KML file in Google Earth

Inssider

Vistumbler  (GPS Capable)

  • Find Wireless access points
  • GPS Support
  • Export/Import access points from Vistumbler TXT/VS1/VSZ or Netstumbler TXT/Text NS1
  • Export access point GPS locations to a google earth kml file or GPX(GPS eXchange format)
  • Live Google Earth Tracking – Auto KML automatically shows access points in google earth.
  • Speaks Signal Strength using sound files, windows sound api, or MIDI

Vistumbler

NetSurveyor

  •  6 graphical, diagnostic views:
    *Timecourse of Beacon Qualities For Each Access Point
    * Differential Display of Beacon Qualities for Each Access Point
    * Usage of Each of the 802.11 Channels
    * Timecourse of the Usage of Each of the Channels
    * Heatmap / Waterfall Chart of the 802.11 Channels
    * Channel Spectrogram of the 802.11 Channels. The more (and different) ways you have at looking at data then the greater the chance something will catch your eye that you might otherwise miss if only a single type of chart were used.
  • Generates reports in Adobe PDF format
  • Powerful and innovative logging and recording capability.NetSurveyor’s playback mode is unique in that it shows you all the recorded data

NetSurveyor

Xirrus

  • Find Wi-Fi networks
  • Managing and troubleshooting Wi-Fi connections
  • Verifying Wi-Fi coverage
  • Locating Wi-Fi devices
  • Detecting rogue APs

Xirrus

What GPS have we used successfully and easily installs in Windows for the GPS Wi-Fi finders above?  The Microsoft GPS Receiver.   The receiver is small, light weight and installs easily.

Microsoft
Our class uses a scientific method of studying wireless and security.  With hands-on during every term (not in a closed lab like a majority of higher-ed institutions), the classes we teach really enjoy the study of wireless and analyzing signals.   During a recent study we found over 380 access points of which 50% were unsecure.

WiGLE has a global map drawn up by wardrivers.   Viewing the maps is scary – really, really scary.  These online GPS maps show secured and unsecured networks.

How to secure your access point- Linksys Belkin Netgear 2wire DLink

Attaching to unknown networks that are unsecured and not public is both dangerous and illegal.   Actually connecting to wireless  hotspots can be dangerous (See our article on attaching to HotSpots).   You should always use a vpn when connecting to a hotspot.   There are now applications that allow laptops, netbooks and droids to be setup as hotspots.  With packet capturing software, your data can be intercepted if you don’t use a vpn.

Improving your wireless signal is actually is easy.  For as little as $40, you can gain (from 30mw) to 1000mw or even 2000mw with the Alpha Antenna.  With a standard laptop, we see approximately eight access points.  With the Alpha we see approximately 14, and with a large antenna we were able to see 44 access points.

So what if you get a larger antenna?  There is a balance of antenna type vs. antenna gain.  A larger antenna can be better,  if it is not too large.


Decibels in relation to power gain:

20 dB is an increase of 100X in power
10 dB is an increase of 10X in power
6 dB is an increase of 4X in power
3 dB is an increase of 2X in power
2 dB is an increase of 1.6X in power
1 dB is an increase of 1.25X in power
0 dB is no increase or decrease in power

Decibels/dB, how to understand their relationship to power loss:

1 dB loss: 80% of power remains.
2 dB loss: 63% of power remains.
3 dB loss: 50% of power remains.
6 dB loss: 25% of power remains.
9 dB loss: 12.5% of power remains.
10 dB loss: 10% of power remains.
12 dB loss: 6.25% of power remains.
20 dB loss: 1 percent of power remains.
(Therefore professional wireless cards have to be used for larger antennas)

(Calculators)

If you add an antenna (yagi, omnidirectional) and need to add cable, make sure the total attenuation or loss is no more than about 3 db at 2.4 GHz or you could lose half of your total transmit power before it even reaches the antenna.

Specs on the Alfa Antenna ~

* Compatible with IEEE 802.11n, 802.11b/g/n wireless standards
* 2.4GHz frequency band, MIMO (Multiple Input Multiple Output)
* Complies with Universal Serial Bus Rev. 2.0 specifications
* High speed transfer TX data rate up to 150 Mbps
* Supports WPS by S/W
* Supports wireless data encryption with 64/128-bit WEP, WPA, WPA2, TKIP, AES
* Wide Range coverage
* Compliant with FCC Part 15.247 for US, ETS 300 328 for Europe
* Works with Windows 2000, XP 32/64, Vista 32/64, Windows 7 32/64.

Specifications:

- IEEE 802.11b/g/n standard
– USB 2.0 standard
– Up to 150Mbps for 802.11n connections
– Frequency Range: 2.412~2.483 GHz
– Receive sensitivity 11b: -92dBm, 11g: -76dBm, 11n: -73dBm@HT20, -70dBm@HT40

Want to further analyze signals? Use a Spectrum Analyzer ($40+).

If you are looking for an economical solution the 2.4 Ghz Spectrum Analyzer by  Ubiquiti  is an excellent buy and is around $40+ – with an external antenna (AirView software is free)  My recent purchase for our class (personal purchase) is an excellent production and teaching tool.

A Spectrum Analyzer normally cost several hundred dollars.  This solution is an excellent solution for viewing the distribution of RF energy in the 2.4GHz band.   By viewing the analyzer, you can determine which channel has the least interference and select an appropriate channel for maximum performance.

See How it works- Link

Product Information

You must purchase the hardware in order to use the software.

Excellent Product for the money.

Over-Provisioning and SSDs

Over-provisioning is the allocating of a specific amount of free space on your SSD.  Over-provisioning improves SSD endurance and performance.   Many SSDs are packaged with software that helps the end user install the drive and to plan for OP.  (More advanced drives are doing away with OP).

The SSD controller manages all of the data that is stored on the drive.  While these drives are really fast, data writes are not just placed on the drive.  Data is moved around and the controller on the drive is programmed to use the drive evenly across the NAND blocks.   By moving the data around, the controller can use the free space (OP) to swap information as needed.     This in turn adds life to your SSD.  Always update your SSD firmware, use the manufacturer’s software for OP if your drive recommends it and don’t forget to trim your hard drive.  TRIM allows for the removal of junk or old data.  How? Easy – Open a command prompt (as Admin)

Type the following – fsutil behavior set DisableDeleteNotify 0

Over-provisioning in Samsung Magician’s software.

OP

Always load the drivers – Below is Intel Drivers on my laptop vs. Windows 8 generic drivers

drivers

Windows 8.1 SSD Optimization

If you have install an SSD to Windows 8 or 8.1, and you aren’t sure if the OS is optimized for an SSD. Here’s the fastest way to make sure it is optimized.

Open a CMD prompt as an Administrator
Run winsat formal
Defrag will remain on, that’s right, on. After ‘seeing’ the SSD, this tool (defrag) will become optimize and will trim your SSD.
Of course AHCI should be on, over provisioning accounted for and the proper chipset drivers loaded.

Configuring WDS to extend your wireless network

Want to extend your network and make it more reliable and robust?   

Here’s what you will need -

  • Two routers with the same firmware
    • Preferably Tomato or DD-WRT

Login to the first router.  

In this example, the static number 192.168.1.1 is the Main router.

  • Enable the WAN to match your ISP  
  • Enable DHCP
  • Enable Access Point + WDS  (Picture two below)
    • You must have the same wireless configuration on both routers
      • Enter the MAC address of router two under WDS Link with.

Router 1 no 1

Router 1 no 2

Login to the second router

  • Disable the WAN
  • Disable DHCP
  • Assign the router a static IP address (Below we have given the router .250)
  • Enter Router One’s IP Address for the Gateway
  • Enter a DNS of your choice
  • Make the wireless configuration the same as the first router.  Under WDS, change the drop down to automatic.

Router 2 no 1

Router 2 no 2

With the same settings, you can now extend your network several hundred feet under the right conditions.  Because the SSIDs are the same, once you join one of the routers with a smartphone or laptop, it will seamlessly change to the stronger signal.

With Tomato, you can chain together approximately 12 devices.

Links-

Tomato RAF

Shibby’s Tomato

DD-WRT

Note; The IP addresses and MAC addresses are in a lab environment.

How does it look on a network map?  The two routers are actually connected together.  The switch is the four ports on the back of the router closest to the internet.

Map

HP Pavilion 11 x360 Review

I usually don’t review hardware products but I felt a need to review HP’s Pavilion 11t-n000 x360.   

My father-in-law wanted a Microsoft Surface but still wanted a keyboard and the functionality of a laptop.   He also wanted to avoid the expense of a Microsoft Surface and wanted something with a small profile, light weight, lots of storage and plenty of ram for traveling.  He found the HP Pavilion 11 x360 that has the following features:

  • Quad core Pentium 2.17 Ghz
  • Windows 8.1 64bit
  • 4 GB DDR3 
  • 500 GB HD 
  • Beats Audio
  • less than 1″ profile
  • Screen 11.6″ (Touchscreen)
  • Gyros built in
  • 1 -USB 3.0
  • 2 -USB 2.0
  • Wireless 802.11
    • Miracast compatible 
  • Ethernet Port
  • 5 hour battery life (45 watt AC adapter)
  • SD Mediacard Reader
  • 12.12 x 8.46 x 0.86 in 
  • 3.08 lbs
  • HDMI
  • TruVision Webcam
  • 1 year warranty

I expected the laptop (netbook?) to be slow.  I was surprised at how responsive it was with 4GB of RAM.  It is by no means a powerful gaming computer but is a match for home, business or school users.   The pc is upgradeable to 8GB and a hybrid hard drive which would make a difference in performance.  Is this necessary for the typical user?  Probably not.

Once you setup a Microsoft account, Windows 8.1 has the Microsoft store (which now has over 400,000 apps ) and OneDrive to backup and sync pictures, files and more. 

With the HP Pavilion 11, you can fold the keyboard to have a tablet or you can flip the keyboard down and use the pc in ‘tent’ mode so it supports the tablet functionality.   Folding the keyboard under the touchscreen gives you a tablet.   The touchscreen is very responsive to the slightest touch.   

20140817_135729      20140817_135748

At $399,  I don’t know why you would buy a laptop or a tablet.   

More Information