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NetworkManager Will Now Roam For WiFi Signals More Aggressively

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  • NetworkManager Will Now Roam For WiFi Signals More Aggressively

    Phoronix: NetworkManager Will Now Roam For WiFi Signals More Aggressively

    NetworkManager has shifted its threshold for a weak WiFi signal for when to begin searching for other WLAN networks. Up to now NetworkManager used a -80dBm threshold for when to roam for other network signals while now that has changed to find hopefully stronger network signals sooner...

    http://www.phoronix.com/scan.php?pag...oam-Aggressive

  • SystemCrasher
    replied
    Exact -dBm depend on radios, they also have certain inaccuracies, 80dBm reading could mean -78dBm in air. Or -82dBm. Or something. Different radios would show different numbers. At whch point radios with overlyoptmistic readings going to suffer even worse. Also radios would usually go for lower modulations, but -80dBm is barely workable for lowest .g modulations, slow and taking plenty of airtime (=risk of airtime problems in "dense" environments). So if it reads -80dBm ... one really better using something else at this poin, if there was such option. Even iDevices eventually show strange behavior being very reluctant to give up on weak AP, even if it barely transfers any data at all, while there is awesome powerful AP nearby, so manual re-connection immediately fixes that. But I thought point of automatic roaming is to ensure user do not have to do that manually.

    Leave a comment:


  • linuxgeex
    replied
    Originally posted by SystemCrasher View Post
    At -80 dBm most wireless radios I've seen would be in "barely works" state, losing numerous packets, it wouldn't reasonably support e.g, watching video, except maybe few lowest youtube resolutions. Granted roaming only happens if there is something better found, I'm not sure how it can make things worse. Though it also subject to SNR, in desert -80dBm would be survivable, but in typical city it means signal is badly damaged by nearby wi-fi signals so it rarely makes through and overall performance is utter crap.
    Agreed, -76dB seems to be the point where TCP starts going to hell with 802.11ac. But keep some statistics on your stations and you'll find that they can vary +-20dB as seen by the client. One of those stations will be the best, even if it's at -76dB and another one temporarily shows -60dB. Also, dB knows nothing of congestion. If NetworkManager doesn't use a higher intelligence than relative dB at a given point in time then this is going to be a disaster.

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  • starshipeleven
    replied
    Originally posted by Jabberwocky View Post
    I would prefer not to talk about this topic on this forum, but the lack of consideration prompts me to highlight a few things...
    I'm not the one using murder statistics to judge a nation's interest in enforcing radio laws, I'm just pointing out that it's tangential here.

    For example in EU you could literally run around with a KW-range radio emitter (say a poorly shielded cheap microwave oven, no shortages of that) and none would even notice, and it would not cause much disruption either. Someone will curse at their smartphone provider and that's it.

    But then you get wifi routers that by law have to prolong boot times by 5 minutes or so to sense the 5Ghz frequencies used by local air traffic radars or some shit to avoid interfering.

    Leave a comment:


  • Jabberwocky
    replied
    Originally posted by starshipeleven View Post
    Does a country where 46 people are killed per day care about that? Because that's USA.
    I would prefer not to talk about this topic on this forum, but the lack of consideration prompts me to highlight a few things...

    USA has estimated 332 million people. ZA has estimated 57 million people. If you compare the stat (46) from your post compared to the 2019 stat (58) and take population into account then a person living in ZA's chance of getting murdered is increased by 734% compared to someone living in USA. The official stats, that I mentioned, are based on end of March 2018 to end of March 2019 which was before the xenophobic attacks started that's currently taking place here, murder is expected to rise in 2020.

    I'm not looking for a pity party, on the contrary I think the average South African and foreigners-in-ZA are doing a great job trying to work hard and keep order. If you do not agree that there's a connection between corruption and murder then we can agree to disagree.

    Back on topic... IMO the amount of WISPs and ISM band congestion is going down in my area. Not due to regulations that are enforced, but rather due to reduced demand for internet over long range WiFi links. Government owned monopoly on landlines has been decreased drastically over the past 15 years. Investing in fibre is a no-brainer in urban areas (now that it's legal).

    Leave a comment:


  • starshipeleven
    replied
    Originally posted by Jabberwocky View Post
    If you bribe someone you get unlimited power! In a country where 58 people are killed per day things like these doesn't really matter.
    Does a country where 46 people are killed per day care about that? Because that's USA.

    Leave a comment:


  • SystemCrasher
    replied
    Originally posted by linuxgeex View Post
    I sure hope that it keeps some statistics about its success rates so it's not madly hopping AP's pointlessly.
    At -80 dBm most wireless radios I've seen would be in "barely works" state, losing numerous packets, it wouldn't reasonably support e.g, watching video, except maybe few lowest youtube resolutions. Granted roaming only happens if there is something better found, I'm not sure how it can make things worse. Though it also subject to SNR, in desert -80dBm would be survivable, but in typical city it means signal is badly damaged by nearby wi-fi signals so it rarely makes through and overall performance is utter crap.

    Leave a comment:


  • Jabberwocky
    replied
    Originally posted by grigi View Post
    Wow, in South Africa the legal limit is 200mw and 100mw. So 5GHz is pretty much always superior.
    But nobody enforces the limits, so one can easily get 1W radios, especially in the Amateur Radio circles...
    Very few people know what the limits are. Buying 1W radios are legal and using it under certain conditions for unlicensed operators is also legal.

    ICASA's rules are quite complicated and, to my knowledge, have not been updated in many years. That said, according to "The Radio Frequency Spectrum Regulations of 2015 (Government Gazette No. 38641)" For wireless the 2.4GHz (2400-2483.5Mhz) has a limit of 100mW EIRP. For wireless the 5.8Ghz is more complicated...
    • Part1 (5150-5350Mhz) has a limit of 200mW EIRP and only allowed indoor
    • Part2 (5470-5725Mhz) has a limit of 1W EIRP
    • Part3 (5725-5875Mhz) has a limit of 4W EIRP (1W radio output power) and many strange/obvious/complex rules that goes with this one.
    These are all rules for unlicensed operator. If you are a certified SARL member you are allowed to do more. If you license a band you are allowed to do more. If you bribe someone you get unlimited power! In a country where 58 people are killed per day things like these doesn't really matter.

    Most devices (which are approved by ICASA) have default radio power set to 100mW and use 6 to 10 dBi antennas, which violates ICASA's EIRP standards.

    Back on topic, I like this change. I would have loved it it was configurable though.

    Leave a comment:


  • carewolf
    replied
    Originally posted by gQuigs View Post

    I believe if you are scanning you can't do as much (or maybe any?) actual network traffic.
    My laptop always get a longer and longer list of neighbour networks even after connected to my regular one, so it must also work passively. Though perhaps only on the same band.

    Leave a comment:


  • gQuigs
    replied
    Originally posted by carewolf View Post
    I must be missing something: Why not scan at the lower levels but just pick the stronger signal?
    I believe if you are scanning you can't do as much (or maybe any?) actual network traffic.

    Leave a comment:

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