SD Card Test


device-2017-01-17-222230Hi guys,

I have a new app on Google Play, called SD Card Test. You can download it using this link.

Using this app, you can test the speed of the internal (built-in) or external (removable) SD card. You can measure both read and write speeds.





Here are a few more screenshots:


Network Signal Monitor for Android

Hello guys!

networksignalmonitor1Let me introduce my new app called Network Signal Monitor. You can download it from Google Play, link here.

This app is very similar to my existing WiFi Analyzer application, but it monitors and analyzes the cellular network of your mobile phone. So it will check your network type like LTE or HSDPA, the latency, signal strength and others.

Main features:
* detailed mobile network information
* detailed SIM information
* analyzing function
* real-time signal strength on the dashboard and on the graph.

As this is a new app, forgive me if you find any error or problem in the app, but feel free to send me your remarks.

Dual SIM devices are also supported, but currently only partially (I’m working on it).

More screenshot about the application:


Mobile Network Glossary

This is an online help for the Network Signal Monitor app.

Signal strength: This is the power of the received signal. The weakest the worst. The acceptable value depends on the given network type. For example -90 dBm is good for an LTE network but low for a GSM network.

MCC: Mobile country code. The mobile country code consists of 3 decimal digits defined by E.212. More details are here.

MNC: Mobile network code. The mobile network code consists of 2 or 3 decimal digits defined by E.212. More details are here.

ASU: Arbitrary Strength Unit (ASU) is an integer value proportional to the received signal strength measured by the mobile phone. More details are here.

IP address: An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, mobile phones) participating in a computer network that uses the Internet Protocol for communication. Example:

latency: This is the latency time of the server in ms.

Disable Adaptive Brightness in Windows 10 / LG monitor

Hi guys,

After I installed Windows 10 to my new computer, I experienced a very annoying thing: the brightness level of the screen went up and down without my intent… I thought it is caused by Windows 10 (but it was only half-true).
Ok, if you google this thing, you will find a lot of articles about how to disable adaptive brightness in Windows 10. Basically go to Control Panel -> Power Options -> Change plan settings -> Advanced and then at the display settings disable Adaptive Brightness.

This did not work…

After reading a tons of forum, I found that my computer has Intel HD 520 VGA and it also contains this feature. So I had to do the following:

Open Intel HD Graphics Control Panel -> Graphics Properties -> Power -> On battery and disable Display Power Saving Technology.

And it still did not work, the brightness of the screen always changed. Very-very frustrating…

Finally, I found the reason of the problem and the solution.


20160923_210153My new LG monitor also knows this “feature”. It’s called as “Smart Energy Saving“.
So the solution: go to monitor menu -> Quick Settings and disable “Smart Energy Saving” function. By default it was set to “Low”. After I turned it off, the problem is gone. No more brightness change excepting if I am changing it.

Hint: some monitor calls this feature as DCR (Dynamic Contrast Ratio).


Disable this function


Iperf on Android with visualization

Hi guys,

Now my WiFi Speed Test Pro app supports Iperf too. Just select IPERF tab, give the IP address and port of the iperf server, then click on start.











Then you can see the result both on speedometer and on visualization tab. Of course don’t forget to start iperf server:


WiFi Tips and Tricks

Hello guys,

In this post, I will share some useful information with you about your WiFi in a question-answer style.

My router supports both 5 GHz and 2.4 GHz WiFi. Which should I use?

Both of course. The trick: give the same name (SSID) for both 2.4 and 5 GHz network, and use the same encryption and password. In a word: use the same settings for both.

The reason: the modern mobiles and laptops are smart. They will prefer using the 5 GHz network when the signal level is high, and will switch to 2.4 GHz when the signal level is low because it has larger range (Note: some devices will only use the signal level information for the decision when you turn on the WiFi).
But it will only work smoothly if they have the same SSID.

My mobile is loosing WiFi connection, the signal level is low. What should I do?

First of all, ensure that a 2.4 GHz network is set. This is the default mostly, but sometimes people thinks 5 GHz is more modern and disable 2.4 GHz. It’s a bad idea, because 5 GHz network has limited range.
The second step is to try to move your router to a better place (closer to your mobile). If it is not possible, then consider to buy a WiFi repeater or another router that support WDS (sometimes a separated router is cheaper than a repeater). Using WDS technology, you can extend your existing WiFi network with this second device easily. The repeater will make stronger the original signal and provide you a better WiFi connection on larger range.
Place the repeater or the second router closer to your main router, for example half-distance from your mobile and half-distance from your router.

Which WiFi security should I use?

DO NOT use OPEN or WEP encryption excepting if you want to share your WiFi (and your Internet) with everybody.
Open = anybody  can attach to your network without your permission.
WEP = this is a very old and very weak encryption. Any script kiddie can break it.

Always use WPA or WPA2.


Always use WPA/WPA2

What about WPS (WiFi Protected Setup)?

You should disable it. WPS is a security risk in your network however it is enabled by default in most cases. There are several problems with WPS:

  • It can contain security hole, and most people never upgrade the firmware of the router (if there is any fix at all).
  • Sometimes the manufacturer are using just only a few default WPS codes. That means if someone knows one of them, he can attach to any other router that are using this code.
    The result is the same: if someone breaks your WPS, he can attach to your network without your permission and without knowing your password.

So the best is if you disable it completely and only enable when you need it.

What about WiFi analyzer apps?  Can they help me?

Yes, of course. Using WiFi analyzer apps, you can identify the problems on your network. They can help you to detect possible bottlenecks and visualize the wireless networks around you.

What about WiFi booster apps? Will they fix a bad WiFi connection on my mobile?

No, they can’t. You can find more details about it here. You shouldn’t install any WiFi booster app excepting if you like watching ads…

Why most routers use channel 1-6-11 on 2.4 GHz?

Because on 2.4 GHz, only the 1-6-11 channels are non-overlapping. A router that uses channel 1 won’t interfere another router that is using channel 6 or 11 and vice versa.
So if there is no any other router around you, you can use any channel, what you want.
But if there are other routers, you should choose only between 1-6-11. Which is less overloaded. This is the point where WiFi analyzer apps can help you.


WiFi analyzer apps can help you to find the best channel

What about 5 GHz?

Because 5 GHz networks have limited range, interference does not cause problem usually.
You should select a channel that is not used by everyone else.

My internet access is slow, but I want to measure the pure performance of my WiFi network. How can I do it?

Well, this is a self-promotion, but in that case, you can use my WiFi Speed Test app. Or if you want to use your computer, you can use my simple java-based client:

WiFi glossary

News (2016.09.02): WiFi Tips & Tricks

SSID: This is the name of a wireless network. SSID is a case sensitive, max 32 alphanumeric character unique identifier. Example: my-network

Access point(AP): Generally, this is your router. A device that allows wireless devices to connect to a wired network using Wi-Fi, or related standards.

AP capabilities: This is the security level of the AP. For example, it can be open (anybody can attach) or encrypted (with different encryption strength like WEP, WPA, WPA2) or even authenticated (username:password). Example: WPA2-PSK-CCMP

MAC address: A media access control address (MAC address), also called physical address, is a unique identifier assigned to network interfaces for communications on the physical network segment. Example: 00:00:00:00:00:01

BSSID: MAC address of the access point. This is also an unique identifier. There can be several APs on the same network (same SSID) with different BSSIDs. Example: 00:00:00:00:00:02

IP address: An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, mobile phones) participating in a computer network that uses the Internet Protocol for communication. Example:

Frequency: All wifi networks operate on a special frequency. The most common is the 2.4 GHz (2412-2484 MHz), or the 5 GHz (4980-5825 MHz).

Channel: Each frequency range is sub-divided into channels with a center frequency and bandwidth, analogous to the way radio and TV broadcast bands are sub-divided. For example: 2412 MHz = channel 1. 2437 MHz = channel 6.

Overlapping channel: the networks operate on close channels can cause interference on each other network. This can cause slow wifi data rate. In the 2.4 GHz band, 1, 6 and 11 are the only non-overlapping channels.

Guest network: Sharing your wifi with “guests”. The AP has dual SSIDs, dual security and the guest network is isolated from other networks.

Possible guest network: in WiFi Network Analyzer app, this message shows that it found a network that seems to be a guest network of the connected network.

WDS (expanded) network: WDS allows a wireless network to be expanded using multiple access points without the traditional requirement for a wired backbone to link them. Using WDS you can extend the range of your wireless network.

Possible WDS (expanded) network:  In WiFi Network Analyzer app, this message shows that it found a network that seems to be an expanded network of the connected network.

Link speed: This is the theoretical data rate. The current value of link speed depends on the distance from the AP, the signal strength, supported protocols by the AP and your mobile. In a wireless network, the link speed is always higher than the real achievable speed. Example: 433 Mpbs.

AP latency: This is the latency time of your access point (router) in ms. If someone generates hard network traffic, this value will be high so you can detect it easily.

Signal strength: This is the power of the received signal. The weakest the worst. A good signal is always higher than -75 dBm. If -90 dBm or lower, this is really bad. Example: -52 dBm.

Device-to-AP RTT support: Round trip time (RTT) between the AP and the mobile device over the WLAN is supported or not.

Wi-Fi Direct support: Wi-Fi Direct allows two devices to establish a direct, peer-to-peer Wi-Fi connection without requiring a wireless router

DFS: Dynamic Frequency Selection. The access points automatically select frequency channels with low interference levels.

No DFS: In WiFi Network Analyzer app, hide the networks that use DFS. The reason: they are using a lot of channels, and it’s not practical to show them by default because the screen will be congested and ugly. You can enable it using this check box.

Useful links:
How to optimize your wifi with Android
WiFi Speed Test guide