Hi there
I need new installation for wide public area
I have 30 AP for this area to cover it my Q what u suggest use 5 GHz or 2.4 GHz , I know low frequency give more range but slow speed and high frequency give small range but high speed , but what is best choice if it public ,
The AP what should I use tplink cpe 510 for 5 GHz with openwrt and cpe 210 if I use 2.4 GHz
"Public" tells me that you don't have control over the clients. As a result, you likely will need at least 2.4 GHz 802.11n, and may even need to (ugh) supply 802.11g (and perhaps even legacy crypto, though I'd guess this is an unencrypted network). If you can avoid 802.11g and other legacy rates, your performance will likely be better.
Personally, I'd deploy a dual-band system. If you're set on TP-Link as a vendor, they supply (edit: indoor) dual-band, 802.11n/ac APs with PoE for under $100 each. Ubiquity has similarly priced units. I have not used either myself.
Edit: Had not realized these might be outdoor deployments. Considerations are more complex with large scale and weatherproofing required.
Nice sound , my problem with 2.4 GHz is I get dead zone with it what I mean with dead zone it's I get signal but I can't connect on it and if I connect I get high ping 1000ms and over , in 5ghz I didn't get this problem if I see signal in my device I can connect on it and play with fine like I near it .
I dont think you should have any dead zones within the range. Because AFAIK TpLink CPEs provide long range coverage and if the APs dont have any obstacles and interference in their coverage to users then everything should be fine even with 2.4Ghz. If you get problems with 2.4Ghz it means there is interference problem and since 5Ghz uses different ranges than 2.4Ghz it's not getting any interference and thats why you seem to have dead zones with 2.4Ghz.
I'd suggest to go with 2.4 ghz but as you know 5 ghz is also becoming more popular these days but it's possible you may not be able to enjoy the long range as 2.4 (as this is my understanding but please correct me if I am wrong) so it's basically down to what you/your users need.
I'd personally prefer to have an option to switch to 5 ghz in the future so if it's possible have something that can support both but for testing you should use 2.4 ghz
and make sure to use less crowded channels. I think you'll only have options between 1, 6 and 11 basically because others just overlap these ones. Choose appropriate places for routers so there's less interference from other devices nearby, etc etc.