Showing posts with label wifi. Show all posts
Showing posts with label wifi. Show all posts

Thursday, January 2, 2014

How to fix poor WIFI reception

Yup, we have all been there, one buys expensive Mimo ( Multiple In/ Multiple Out ) WIFI routers with 2 or more antennas after having done extensive online research on what to buy. But, vendors dont really tell you how to set up a proper WIFI setup that is optimized for maximum bandwidth & coverage. So, before you start cursing the seller, fear not, WIFI reception problems can be fixed as explained below. 




Take above example, where one has multiple wifi access devices sharing a wifi router. Due to some unavoidable circumstances such as number of walls, dead spots where you get zero reception, interference of cordless phones, microwaves  between wifi router and client devices etc, you end with very poor reception. But, this can be fixed by relocating the wifi router to a different part of the premises if its possible, or, take existing wifi equipment and boosting the reception, using items found at home, without buying additional wifi routers/ repeaters depending on how large the house is.

How a WIFI router works is - transmit the signals in all directions, therefore they are called  " omni directional ". Now, if you want wifi coverage only inside the premises, there would be no point allowing wifi signals to broadcast outside said premises. So, how does one make an omni directional to a directional antenna without spending more money on specific antennas. You build it yourself taking existing omni directional antenna and make it directional. 






Following household items are required to boost wifi  reception -

1) WIFI N spec Router with 2 or more antennas 
2) Cardboard 
3) Scissors
4) Duct tape
5) Waste bin
6) Big Juice Strainer 
7) Aluminium Foil
8) Wifi Analyser android app or similar app


Following experiment uses two WIFI N spec routers, router 1 - 2 omni directional antennas and, router 2 - an antenna-less " travel " WIFI N spec router.  

  • Take a piece of thick cardboard [ otherwise it wont be able to stand vertically for long ] and cut it to this shape as seen here, have to specify, height of the cardboard has to be larger than the wifi antenna on the router, otherwise, part of the wifi goes out of the house and some re focus into the house. 



cardboard for directional wifi reception
  • Duct tape above cardboard and then fold on the two sides as seen here thus making a directional antenna. Why duct tape it, then, this flimsy cardboard becomes durable, water resistant and looks rather cool for example. You can if you like, pass through some fishing tackle wire from left  to right lids, so it holds that bent shape indefinitely. I simply kept a old laptop hard disk behind this booster stand so it doesnt fall down backwards. 
partially completed wifi reception booster


  • Lastly, take aluminium foil and wrap completely the cardboard directional antenna stand, making sure, if possible, depending on type of foil used, where one side is dull & other shiny, to put the shiny side facing inwards so it reflects wifi signals back towards the front of the router as seen below. 




  • Does the aluminium foil have to be crumpled as seen in this picture, well, nope. I salvaged this foil used to make my dinner. 
  • The big heatsink as seen here, on top of the router is an optional add-on, where it is used for cooling the router, does it need a fan ? or do you even need a heatsink ?  that is entirely upto the end user. 


Without wifi booster - 



With wifi booster - 

Router 1 - Boosted

Router 2 - Boosted
  • Considering Router 2 is an antenna less device, the improvement of reception with the aluminium booster did take me by surprise. Tho the router 2 booster was just assembled without using any cardboard,  to see if there was a noticeable difference, there was a big one. Therefore, a proper shield made with cardboard as seen being used for router 1 or with similar material will be built within the day. Overall - this was a successful & fun project indeed.

temporary make shift wifi booster for router 2
  • Better wifi reflector was built afterwards using a juice strainer and some duct tape mounted on a wastebin. On a plus side, this whole unit can be moved with ease depending on the end user.


  • After proper reflector was made using juice strainer, wifi reception dramatically improved. I chose a plastic juice strainer as opposed to metal strainer coz former is very light weight and if duct taped completely around the wastebin, it should hold in place for longer as opposed to just using a piece of duct tape measuring just 5 inches in length. Also do note both sides of the strainer was covered in using a " single " piece of aluminium foil.    




further boosted wifi reception on Router 2


  • Out of curiosity, i changed the Router 2 orientation from landscape to portrait and to my utter shock, it further improved reception. Therefore one can deduce, even tho this router is a omni directional, signals transmit top to bottom direction or as seen here - front to back of router. Thus this parabolic antenna re focuses & concentrates omni directional wifi signals. 
  • Do note, once this booster is installed on the router, you will loose some wifi signal coverage if you were to stand behind it, as this [ aluminium directional booster ] converts omni directional to directional. Proper placement of router + booster shield is key if one wants to enjoy better wifi reception. 
  • As a further signal improvement test, I raised the whole unit by 2 feet off the ground and to my shock, it further boosted wifi reception. Which brings me to this conclusion - higher the wifi antenna in relation to physical obstructions in  house, better signal coverage. When tested with/ without aluminium parabolic shield, there was a sharp drop in signal strength     [ -40 dbm with shield / -70 dbm without shield measured 150 feet away from device ]  having being kept exactly at same position - 2 feet of the ground.  
  • As seen on wifi analyser, best signal coverage is between -60 dbm & -40 dbm. 
Raised off the ground by 2 feet

Now needle is stuck at -40 dbm 
    • You can also make this booster out of a beer can or two - one reflector per antenna or one big reflector for all antennas.


    Wednesday, November 20, 2013

    Android Devices & Battery Life - Duel to the Death




    WIFI Home Network

    WIFI Networks - 


    Wireless networks operate using radio frequency (RF) technology, a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space.

    The cornerstone of a wireless network is a device known as an access point (AP). The primary job of an access point is to broadcast a wireless signal that computers can detect and "tune" into. Since wireless networks are usually connected to wired ones, an access point also often serves as a link to the resources available on the a wired network, such as an Internet connection.

    In order to connect to an access point and join a wireless network, computers, smart phones etc, must be equipped with wireless network adapters. These are often built right into the device whether it be a computer, mobile phone or a  tablet. 

    DHCP - 

    Short for Dynamic Host Configuration Protocol, a protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. In some systems, the device's IP address can even change while it is still connected. DHCP also supports a mix of static and dynamic IP addresses.

    Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. This means that a new computer can be added to a network without the hassle of manually assigning it a unique IP address. Many ISPs use dynamic IP addressing for dial-up users.

    TCP - 

    Short for Transmission Control Protocol. where Connections must be properly established in a multi-step handshake process (connection establishment) before entering the data transfer phase. After data transmission is completed, the connection termination closes established virtual circuits and releases all allocated resources.

    Unification of these principles - 

    • If one were to bridge these three technologies together with a screen & dial pad, it would become a   " wireless access device " or smart phone/tablet.
    • Therefore, a smart phone/tablet, would have to go through the following steps each & every time it needs to make a " wireless connection " to the Internet.                         Turn on wifi antenna > scan for an access point > authentication between  access point/ wifi access device >  request an IP > bind to that IP >  establish a IP connection between AP & host > data transmission > termination of TCP connection > Turn off wifi antenna > return to stand by mode. 
    • Power is required for all of the above steps, which drains smart phone battery, each & every time a wifi connection is made. 
    • If a device is in " sleep mode " with no wifi data transmission , wifi antenna should not be drawing in power. 

     Before 

    23:41 - 02:05 17- 18 Nov 2013


    Galaxy Note 1 -  2 days max use
    • Notice at 23:41 battery level reading = 93 %. At 02:05 battery level reading = 77 %. Therefore battery dropped by 16 % in 2.5 hours. In both cases, phone was in " airplane mode " & wifi turned off. Yet colossal battery drain in stand by. [  If WIFI is enabled & the user selects " airplane mode " via desktop widget or by going to " Settings/ More settings / ", WIFI is disabled, but, can be enabled by  pulling down the menu [ i forget the name for it at the moment ] in home screen. Then, even though you are in " airplane mode ", you can use WIFI in offline mode ]

      After 


      01:31 - 09:16 20 Nov 2013

      09:16 - 13:27 20 Nov 2013


      Galaxy Note 1 - 13 days max use


      • Notice at 01:31 battery level reading = 58 %. At 13:27 battery level reading = 43 %. Therefore battery dropped by 15 % in 12 hours. In both cases, phone was in " airplane mode" & wifi turned off. Whoa !!! hold it right there you ask, How can this be ? before i answer that, i like to point out, above are some of the actual screen shots of battery statistics collected in real time

      These tweaks can be done on either rooted/ non rooted android phone/ tablets

      Automatic display brightness adjustment

      Settings/ WIFI/ Advanced


      1. Go to Settings/ WIFI/ Advanced/ - Disable ( uncheck ) " Network Notifications " [ Network Notification = as most know, WIFI scans for Access Points/ Routers at pre determined times. Which uses up battery power nevertheless. So if you have pre configured WIFI access points, eg { home/office } WIFI networks, there is no need for it be pulsing so many seconds to see if there is a WIFI AP by that name. " Network Notifications has nothing to do with incoming sms/ email/ chat alerts,  all it does is, let the user know if a WIFI AP/ hotspot is nearby ]. " Keep WIFI on during sleep " = NEVER [ Increases data usage ]. Default settings for " Keep WIFI on during sleep " = ALWAYS = Faster battery drain.
      2. I need to explain what the above sentence means because, it was staring right in my face but i overlooked it. " Keep WIFI on during sleep = Always " means, in simple english, DONT turn off WIFI even when in stand by mode. WIFI is just like any antenna, draining power whether you use it or not. So, " why is a WIFI antenna continue to supply with power " when its not being used ? doesnt make any sense to keep it at default = faster battery drain. Now this is the funny part, okay, you might ask yourself, it has to be a firmware bug. But, in truth, this " default " setting has been " in effect " from the very first android device made. Now, comes the more interesting quirk to it, this tweak varies from phone/ tablet to phone/ tablet. These settings even though you change it to " Never " defaults back to  " Always " for some devices, even with latest android firmware. I was lucky with 3 android devices, where this tweak didnt default back to " Always ". Therefore, id say, try it and see, you might need to re check the " Advanced "settings to verify that fact. Do this test on a full battery charge. So why does it say " Never = Increases data usage " ? that i suspect, was added there, to fool the user into selecting  " Always " option. I did note down, data usage counters for both WIFI/ 3.75G at 01:31 and at 13:27, to my utter shock, there was zero data usage during that time period. Screenshots of battery usage during that 12 hour period speaks volumes in itself. 
      3. Location Services ] - " Disable " ( uncheck ) Use wireless networks/ Use GPS satellites/ Location & google search.  [ enable/ disable them when & you require their functionality. ] 
      4. Shutdown/ Restart the smartphone/ tablet once every 3 days is another good practice.
      5. Similar tweak can be done to 3.5G/ 3.75G/ 4G [ Settings/ More settings/ Mobile Networks/ Network Mode = GSM/WCDMA/ GSM ONLY/ WCDMA ONLY ]. Voice calls always use 2G bandwidth even though 3.75G/ 4G is enabled on the smartphone/ tablet. Therefore, that " extra  " 1.75G is just draining the battery faster. I would recommend, disabling 3.75G/ 4G during a voice calls and enabling 3.75G/4G only when its necessary. This rule doesnt apply if one were to initiate a video call where 3.75G/4G " has " to be used for that task. If service provider permits, enable 2.5G or Edge for normal day to day use together with voice as that function is not very taxing on the battery.
      6. Additional  [ Developer Options ] tweaks can be done, they may or may not extend battery life. 

        Developer Options performance tweaks


        [ Developer Options need be enabled before following tweaks ]

        1.  Window animation scale/ Transition animation scale/ Animator duration scale/ = OFF. What these 3 options do is, free up CPU/GPU resources which use considerable battery power. If one can do without these        " fancy gimmicks ", you will notice a much faster & responsive phone/ tablet. [ personally, I keep Transition animation scale = 0.5 and disable the other two. ] 
        2. " Enable ( check ) [ Do not keep activities ] " is an optional tweak, which basically wipes user data upon the user exiting that app, thus freeing up memory/cpu/gpu cycles. [ see, what usually happens is when an user exits a running app by pressing Back button, you minimize the app, but app continues to run in the background consuming battery/cpu/memory resources. That is why, after i exit an app, I manually clear background running app either via a dedicated app such as Clean Master or, android OS specific native Task Manager/ RAM Manager/ Clear memory " Synology NAS & DS File android app ", may have problems in file transfers to & from NAS. 

          01:40 20 Nov 2013 57 % battery level,
          30.79 MB 3.5G Data usage

          08:38 20 Nov 2013 54 % battery level,
          30.79 MB 3.5G Data usage 

          Apps used in this article to monitor android smartphone/ tablet - Google Play Store

          • Clean Master [ comes with a inbuilt desktop widget called " 1 Tab Boost " ]
          • Battery Monitor Widget 
          • 3G Watchdog
          • Airplane Mode Widget by Jason Hull

          Sunday, November 10, 2013

          In Car On-The-Go Internet using a 4G router - TP Link MR 3020


          TP Link MR 3020 4G router

          Package contents
          ( not included in the package is a usb car adapter
          [optional accessory ]  )

          Share the freedom of 4G! Powered by a laptop or power adapter, the TL-MR3020 allows you to easily share a 3G/4G mobile connection with family and friends practically anywhere. By connecting a 3G/4G USB modem to the router, a 3G or 4G Wi-Fi hotspot is instantly established. If your exsting device does not support 4G sharing, please upgrade it to the latest firmware.

          Travel-sized Design and Mini USB Port

          What makes this router so convenient is its’ travel-sized design and Mini USB Port that can be connected to any Laptop or Power Adapter for power. As long as you have your laptop, the TL-MR3020 you can create a wireless cloud that can be shared by iPads, iTouches, Android Phones, Kindles and the vast majority of other portable Wi-Fi enabled devices. 

          High Compatibility Globally-Tested in Field

          Compatibility is the most important aspect to consider when you're selecting a 3G/4G router. To ensure the best compatibility between our routers and the modem you would use with the router, TP-LINK has made certain that our 3G/4G Routers are compatible with the ISPs in the regions in which they are sold. We have teams around the globe continually testing our routers with newly emerged modems to ensure that end users can feel confident that their routers will operate flawlessly where they live and work.

          IP QoS – Control Your Bandwidth

          With Quality of Service (QoS), you can determine how much bandwidth is allocated to each application. This ensures optimum utilization of bandwidth by controlling congestion and preventing bandwidth abuse. This way, users of a small network receive committed and specific bandwidth, preventing non-critical applications from degrading network performance.
          Flexible Power Supply

          TL-MR3020 provides you with a mini USB port to be connected to your laptop or power adapter for power.

          Easy to Use

          The TL-MR3020 can be installed quickly and easily almost anywhere. All you need to do is insert the USB modem into a router, search for its wireless SSID on your computer, and then connect to it. You can be online and surfing the internet in no time! Plus, a user guide is included in the provided CD to help you easily set up your wireless internet connections.


          One Button Security Setup

          The TL-MR3020 features Wi-Fi Protected Setup (WPS) which allows you to setup your security by simply pressing the "WPS" button. This automatically establishes a WPA2 secure connection which is more secure than WEP encryptions. Not only is WPA2 faster than normal security setups, you won’t have to remember a password!


          Features

          Share a 3G mobile connection, compatible with 120+ UMTS/HSPA/EVDO 3G USB modems
          Portable design, light and small enough for you to take anywhere
          Wireless N speed up to 150Mbps
          Quick security setup, faster and safer
          IP-based bandwidth control allows administrators to determine how much bandwidth is allotted to each connected device
          A mini USB port to be connected to your laptop or power adapter for power supply
          3G/WAN failover guarantees an "always-online" internet connection
          Three working modes: 3G Router, Travel Router (AP), WISP Client Router

          Package Content

          TL-MR3020 Router [ latest firmware updates required to get best use ]
          Quick Installation Guide
          Power Adapter
          USB Cable
          Resource CD
          Ethernet Cable  

          DIY In car wifi on the go 

          Items required -
          • TP Link MR 3020 router 
          • USB cable provided in the box
          • USB cigarette lighter adapter to power the router
          • 4G USB Dongle with data plan & SIM



          • pre configure the router via web interface before car install
          • since the router has a range of 300 meters, which is more than enough to envelope the entire vehicle in a WIFI bubble, thus enabling everyone in it to use " on the go wifi "
          • why use 4G using a wifi router as opposed to a 4G SIM inserted to a 4G device ? whatever signal whether it be wifi or 4G has to travel the distance from wifi enabled device to base station, longer the distance, more power required, thus faster device battery drain. If one were to isolate that power requirement needed to go that " extra mile ", you would be drawing significantly less power as both wifi access device & 4G router is in a 30 foot square area or less. Only problem with this setup is, sudden drops of 4G signal coverage in transit from city to city. And the 4G router can be located anywhere inside the vehicle within reach of a cigarette lighter socket.  
          • warning - Do not firmware update via wifi but through LAN cable directly plugged into the 4G router to avoid bricking the router. 



          4G wifi access configuration 

          wifi router signal strength measured at a distance of 300 meters
          from router 

          38 Mb/s mobile wifi download speed 

          Wire 2 needs to be used = 2A current is needed to power on this router
          Mobile Broadband powered up inside the car