Tag: Wi-Fi

  • Awful Bluetooth Audio Quality on Galaxy S7

    Since I have my Galaxy S7, I only connected it twice with my Philips Bluetooth headphones CB8100. Once to play with an Oculus Game and once to listen music. Twice, I was surprised how bad was the reception. Sound was crackly and skipping continuously. It was due to the WiFi !!

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    When I used my headphones to play an Oculus gamen I thought that the mobile was not powerful enough to stream the sound via Bluetooth while playing the video. Weird, but ok… it was also not powerful enough to mirror the video on my Samsung TV, so….

    But when it failed also to stream fluently music, either from YouTube or from by DS Audio Stations (Synology), I thought there should be a reason behind this.

    As it’s known that Bluetooth and WiFi are both using the frequency 2.4GHz, I tried to disable the WiFi… and it solved immediately the problem.

    I never never had such a problem with my previous mobiles 🙁 Also, I am quite sure I would not have that issue if I could connect on a WiFi 5Ghz.

    Support page for GS7 in Belgium is: http://www.samsung.com/be_fr/support/model/SM-G935FZDALUX

    Awful support from Samsung!

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    I did post a request for support to Samsung on the 2nd May and only got an answer on 20th May. I said that the noise was awful when the Wifi was on and great if it was off. I also said that I had not such issue when streaming from my 300€ OnePlus One mobile (the S7 was 799€) or from my Sony Laptop or from my Lenovo Tablets.

    They answered that “Samsung does not guarantee the proper functioning of Samsung products. with other branded”

    WTF Samsung! Wi-Fi and Bluetooth are standard wireless protocols. My headset works perfect with 3 other brands.

    Numéro de dossier client : 2812699319

    Merci pour votre courriel concernant votre Galaxy S7. Vous indiquez que vous avez un fonctionnement anormal avec votre casque Philips tout en ayant le Wifi activé.

    Nous vous informons que Samsung n’assure pas le bon fonctionnement des produits de marque différente que Samsung avec des produits Samsung.

    Si vous avez des questions vous pouvez toujours contacter notre centre de contact. Cela peut se faire par téléphone, par courriel, Facebook ou Twitter.

    Cordialement,

    EL HARIM Med

    Customer Care Representative

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  • Wi-Fi issues…

    Information possibly useful to understand, investigate and solve Wi-Fi issues.

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    Here is a really interesting paper. I did copy the most useful part here:

    • 0.5-2 Mbps: Is enough for chatting and mailing services, though it will slow down some content-heavy websites for users with a 20+ Mbps download bandwidth.
    • 4-5 Mbps: Enough for handling all websites and basic video streaming.
    • 20+ Mbps: Minimum required for HD streaming. Typical bitrate of a 720p iTunes TV show is 2-6Mbps, but routers need to compensate for dropouts, other connected clients and prebuffering…
    • 50+ Mbps: Enough for 1080p movies and over-the-air backups.

    Some routers have a “Power savings” mode to save a few milliwatts. Unfortunately reduces bandwidth disproportionately.

    By doubling the distance between a router and a client, the throughput could shrink to one-third of its original value.

    Water acts as a blockade for 2.42GHz signals: Get all objects that contain any form of liquids out of the way Including radiators, flower pots, aquarium, …

    Also make sure that metal objects are not in the way of the router and the clients.

    Smooth and shiny surfaces are prone to reflecting signals and thus either creating drops or massive signal problems.

    Use a Wi-Fi heatmapping tool to measure the impact of distance, frequency changes and building structures on signal strength such as Heatmapper for Windows.

    Motherboards are working in the “Gigahertz” spectrum. That “noise” is being picked up by built-in Wi-Fi transmitter and the higher that noise is, the more likely it is for your wireless adapter to lower bandwidth automatically. As CPUs these days clock dynamically, the Wi-Fi adapter needs to constantly adapt the link rate which not only causes a variation in Mbps but may also be the cause for dropped connections. Especially on laptops, the Wi-Fi adapter is often built close to the memory and CPU bus, which is a major source for problems.

    Modern routers with “dualband” send two network signals: one at 2.4GHz which is crowded, and one at 5GHz, which is far less crowded and offers more channels. Keep both networks enabled on the router, connect the mobile devices to the 2.4 GHz network (as they other don’t supprt 5GHz) and enable only the 5GHz network on laptops and desktops.

    If choosing the 5GHz frequency band is not possible on the laptops/desktops, limit the router to sending out signals at intervals of 20MHz. It might reduce overall throughput a bit, but it will give a stronger signal with less dropouts.

    Reminder: all info above come form a paper of Sandro Villinger posted on TechWorld.

    Other information I have collected:

    WiFi Channels/Frequencies
    WiFi Channels/Frequencies

    Here in Europe, the frequency 2450 MHz is used by microwave ovens. Those could possibly disturb the Wi-Fi channels 9 and 10 that are both next to 2450 MHz. But if one does, it must be replaced immediately! Radiation that escapes from a microwave oven while it is in use may not exceed 5 mW (per cm2 at a distance of 5 cm). So, if your experience Wi-Fi issues when using a microwave oven, the leakage radiation is probably exceeding a lot that limit (It happens as some of my colleagues already experienced).

    Frequencies from 2400 to 2450 MHz (Wi-Fi channels 1 to 8) are used by “radio amateur”. Those could impact the Wi-Fi signal as their radio signal goes up to 120 Watts while Wi-Fi is usually around ~18-30 mWatts.

    Channels 1, 5, 9 and 13 are known to be used by some wireless transmitter and camera (at least here in Europe). Based on this info and those above, channel 13 seems to be the best candidate to avoid issues. InSSIDer is a tool for Windows that can be used to get information on channel usage in the area.

    Use iPerf to measure the improvement of the Wi-Fi signal.

    Before moving to the channel 13, my Wi-fi signal was lost every few seconds… Since it is on the channel 13, it’s stable as a rock!

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  • “Authentication Error Occurred” with my Samsung Galaxy – Android 4.1.2 – due to Wi-Fi

    Depending on the place where I was located at home, when trying to connect my Galaxy via Wi-Fi, I could got or not this infamous message “Authentication Error Occurred”. I did possibly solve it by changing the channel of my access points.

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    My experience with this error message is that it really depends on the received signal(s) and possibly having several network with the same SSID.

    I have 3 Wi-Fi Access Points in my house. All are configured with the same password and encryption (WPA2/AES), the same SSID and the same channel. This is creating a large and stable wireless network in the house.

    But at some locations where I get either a poor signal or two signals of quite the same strength, I get the infamous “Authentication Error Occurred” message with my Galaxy SII (Android 4.1.2) just after enabling Wi-Fi. And I get this message whatever Access Point I am trying to connect from those locations.

    At those very same locations, my laptop “Sony Vaio” (Windows 8) can connect without any issue, as well as my tablet “Nabi 2” (Android 4.0.4). Reason why I conclude it’s probably an “Android/Galaxy issue” and not a “Router/Access Point issue”.

    Moving from those locations just a few meters away, I can successfully connect quite immediately after enabling the Wi-Fi. But in such cases, although I only moved a few meters away, I get at least one signal much better than the others.

    My access Points are “Devolo DLAN 200 Wireless N”. From security/encryption point of view, they only support WPA/TKIP and WPA2/AES. I tried both mode without success.

    I also tried to use shorter password (minimum being 8 chars) without success. But I admit I didn’t try to connect using WPS (which is supported by my Devolo and reported by some users on various blog to solve this issue).

    I finally tried to completely disable the security/encryption. I did enable the MAC filtering instead. In that mode, the connections succeed really more often, but still not always. And there is at least one location where I can never connect with my Galaxy SII although I can with my laptop and my tablet: my bed 🙁

    During my tests, I was monitoring the wireless signals using “Wi-Fi Analyzer”, to be sure that the signal was kept “fair”. So, loosing the signal for any reason is not presumed to be the issue either, especially as far as I was doing the same test (I.e.: I enable the Wi-Fi and wait for a connection) simultaneously with my Galaxy SII Android 4.1.2 and my Nabi 2 Android 4.0.4.

    As the quality of the signal was “fair” and as far as I had no issue in most other locations with free Wi-Fi, I started to consider that the problem was possibly related to some small signal disruptions in my area.

    Here in Europe, the frequency 2450 MHz is used by microwave ovens. Those could possibly disturb the Wi-Fi channels 9 and 10. But if your does, change it immediately ! Radiation that escapes from a microwave oven while it is in use may not exceed 5 mW (per cm2 at a distance of 5 cm ). So, if your experience Wi-Fi issues when using your microwave oven, the leakage radiation is probably exceeding a lot that limit (It happens as some of my colleagues already experienced). But I don’t have any special device turned on when I do my tests…

    Looking for more information about Wi-Fi signals, I discovered that frequencies from 2400 to 2450 MHz (Wi-Fi channels 1 to 8) are used by “radio amateur”. Those could effectively impact the Wi-Fi signal as their radio signal goes up to 120 Watts while Wi-Fi is usually around ~18-30 mWatts. It would therefore be advisable to check within the neighborhood if anyone has such a hobby. This could likely be the case if the Wi-Fi issues are only experienced during certain period of the day (e.g.: the evening) or during the weekend.

    I finally read that channels 1, 5, 9 and 13 are known to be used by some wireless transmitter and camera (at least here in Europe). As I don’t have such devices, and taking into account the info about the frequencies used by “ham radio”, I decided to use the channel 9 or 13.

    Concretely I did switch from channel 6 to channel 13 on all my access points and could immediately connect flawlessly from all locations where I was experiencing issues previously. That being said, there are possibly some other locations still to be discovered where I will experience again the problem. But for sure, changing the frequency has an impact on the connection!

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  • Laptop’s Wi-Fi off after Windows 8 Update

    My  laptop Sony Vaio VGN CR31 has just rebooted after a Windows Update. Before the reboot, I was still browsing internet via the wifi connection. But after the reboot, the WiFi was OFF(*) although the WiFi switch (on the left side of the latop) was ON.

    (*)  In the network connection panel, the Wi-Fi was showing “Wi-Fi (Off)”.

    I did run the Windows troubleshooting on the internet connection and network adapter.  All drivers were up to date and no issue were found.

    After various attempt to uninstall the latest updates, I found the solution:

    • Press :win: + C  to open Windows 8 Charms menu
    • Choose “Settings”,
    • Click “Change PC Settings” at the bottom.
    • Choose the “Wireless” section. There, you can see two (or three) toggles: Airplane Mode, Wireless Devicess (and possibly Bluetooth).

    Wi-Fi was also turned OFF! Toggling Wi-Fi back ON fixed my issue. No idea why the Windows Updates (or the reboot or ???) did change that settings ?!

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