WEBVTT 00:00:00.000 --> 00:00:15.680 Hello everyone and welcome to the third installment of our Encore wireless section. 00:00:15.680 --> 00:00:20.480 In this section we're going to be talking about how to place your APs to get the best 00:00:20.480 --> 00:00:23.680 coverage and things to keep in mind when you're dealing with your APs. 00:00:23.680 --> 00:00:27.760 This is a really short lesson but a very important one. 00:00:27.760 --> 00:00:32.840 Placing your AP in your environment is all about maximizing the signal without leaking 00:00:32.840 --> 00:00:35.680 outside of the bounds of your building. 00:00:35.680 --> 00:00:40.360 Remember we're dealing with a signal that it can be picked up by anyone. 00:00:40.360 --> 00:00:46.280 So having it extend beyond your physical walls, having that wireless signal shoot out into 00:00:46.280 --> 00:00:51.240 the street, not really a good idea even with security and stuff in place. 00:00:51.240 --> 00:00:55.480 You really don't want that wireless signal going too far out of bounds. 00:00:55.480 --> 00:01:00.160 So let's go ahead and dive into how this actually works. 00:01:00.160 --> 00:01:06.560 Now one of the first things that we're going to talk about within the wireless AP placement 00:01:06.560 --> 00:01:09.080 is the AP effectiveness. 00:01:09.080 --> 00:01:13.200 Where can I place an AP to make it the most effective? 00:01:13.200 --> 00:01:19.800 And the first thing you need to know is the closer you are to the signal, the better the 00:01:19.800 --> 00:01:21.080 signal. 00:01:21.080 --> 00:01:23.760 And that doesn't seem like too much of a stretch. 00:01:23.760 --> 00:01:27.480 You can see we have a higher PHI rate, P-H-I. 00:01:27.480 --> 00:01:32.800 Now the PHI rate basically means the physical rate, that's what it stands for. 00:01:32.800 --> 00:01:38.280 And all that means is the bit rate of the actual data. 00:01:38.280 --> 00:01:44.240 The closer you are to the center, the better you are. 00:01:44.240 --> 00:01:47.720 The further you are away, the worse it gets. 00:01:47.720 --> 00:01:54.600 Now this is, the size from here to here is dependent on what technology you use. 00:01:54.600 --> 00:02:01.720 If you use 2.4 GHz, that has a lower data rate, but it travels farther. 00:02:01.720 --> 00:02:07.880 So the data gets further, further. 00:02:07.880 --> 00:02:12.600 Now if I use 5 and 6 GHz, this is much shorter. 00:02:12.600 --> 00:02:20.120 The effective rate of the data is much shorter, but you get much more data in that area. 00:02:20.120 --> 00:02:25.800 So there is a definite trade-off as you go up in technologies to how far your wireless 00:02:25.800 --> 00:02:29.840 access points will be able to deliver bit rates. 00:02:29.840 --> 00:02:34.840 Now that brings up this, the actual design and placement. 00:02:34.840 --> 00:02:38.520 We now need to ensure coverage in our building. 00:02:38.520 --> 00:02:43.800 In order to ensure coverage, we have to have what's known as overlapping circles. 00:02:43.800 --> 00:02:48.080 You see how we have kind of like a Venn diagram. 00:02:48.080 --> 00:02:53.840 This is our cells, each one of these is called a cell, and we want them to overlap. 00:02:53.840 --> 00:03:00.160 We want them touching because I don't want a person like right here who has no wireless coverage. 00:03:00.160 --> 00:03:05.720 I want wireless coverage throughout the entire building or the entire floor. 00:03:05.720 --> 00:03:09.040 So that means I want these to be overlapping. 00:03:09.040 --> 00:03:16.520 I want the cells to look more like this, so that there's no free space in between. 00:03:16.520 --> 00:03:19.720 There's no place where you're not getting wireless coverage. 00:03:19.720 --> 00:03:26.960 And how we do that, and how we implement that, it depends greatly on the antennas we're using. 00:03:26.960 --> 00:03:29.360 Are we using omnidirectional antennas? 00:03:29.360 --> 00:03:32.320 Are we using directional antennas? 00:03:32.320 --> 00:03:37.440 The best way to do this, the best way I've found, is start at the edges. 00:03:37.440 --> 00:03:40.920 If I have a room, let's do a room here. 00:03:40.920 --> 00:03:49.080 I have a room, and I place my AP here, and I place my AP here, and I place my AP here, 00:03:49.080 --> 00:03:54.800 and here, and then I have an AP here, and here, and one here. 00:03:54.800 --> 00:03:56.680 Well, now I have full coverage. 00:03:56.680 --> 00:03:58.680 What I can do is I can start filling in. 00:03:58.680 --> 00:04:05.200 I can say, oh, I need coverage here, and here, and here, and here, and here. 00:04:05.200 --> 00:04:09.320 And I just kind of honeycomb effect all the way in the middle. 00:04:09.320 --> 00:04:14.920 But by starting at the edges, I can ensure that I work my way in. 00:04:14.920 --> 00:04:19.760 Now it's important to realize, remember when we talked about those different channels, 00:04:19.760 --> 00:04:23.600 we want to make sure that adjacent channels are different. 00:04:23.600 --> 00:04:28.200 If I didn't have an adjacent channel, let's say up here, where it's 64, I'm going to cross 00:04:28.200 --> 00:04:32.160 that out and put 116. 00:04:32.160 --> 00:04:36.600 So I have two 116s that actually overlap each other. 00:04:36.600 --> 00:04:37.600 What am I going to have? 00:04:37.600 --> 00:04:40.120 I'm going to have a ton of interference right here. 00:04:40.120 --> 00:04:41.560 That's not good. 00:04:41.560 --> 00:04:43.840 We want to make sure that the channels are different. 00:04:43.840 --> 00:04:47.720 Remember, we're using a smaller band of the frequency. 00:04:47.720 --> 00:04:53.920 So I'm not going to get any interference when I'm using 64, 116, 36, 48. 00:04:53.920 --> 00:04:55.600 None of these are touching. 00:04:55.600 --> 00:05:01.560 It would be okay if I had a 36 here again because it's not touching the area or cell 00:05:01.560 --> 00:05:03.720 that has channel 36 running. 00:05:03.720 --> 00:05:06.240 I'm not using the same frequencies. 00:05:06.240 --> 00:05:11.360 So that even though it's five gigahertz or whatever I'm using, remember we're using those 00:05:11.360 --> 00:05:21.480 20 to 22 megahertz bands within this range that gives me that difference or that little 00:05:21.480 --> 00:05:25.160 bit of uniqueness in my band. 00:05:25.160 --> 00:05:29.560 So I'm not creating interference to other ones that attach to me. 00:05:29.560 --> 00:05:35.160 Now remember for client density, you're going to want to pay attention to this. 00:05:35.160 --> 00:05:38.400 This differs on APs and antenna types. 00:05:38.400 --> 00:05:42.440 Client density, how many people are sitting here? 00:05:42.440 --> 00:05:44.000 That's going to determine a lot. 00:05:44.000 --> 00:05:46.800 How many different SSIDs you're using? 00:05:46.800 --> 00:05:50.660 How is your wireless LAN controller placement? 00:05:50.660 --> 00:05:53.640 Who needs to be on what SSID? 00:05:53.640 --> 00:05:55.560 How do they need to roam? 00:05:55.560 --> 00:05:58.240 All that stuff is going to come into play later. 00:05:58.240 --> 00:06:01.000 We're going to have a discussion of that in architecture. 00:06:01.000 --> 00:06:07.120 But when we're talking about basic coverage, when we're talking about an AP and its placement, 00:06:07.120 --> 00:06:09.280 this is what I want you to think about. 00:06:09.280 --> 00:06:11.560 Start at the edges, fill your way in. 00:06:11.560 --> 00:06:13.160 How many people are sitting there? 00:06:13.160 --> 00:06:16.320 That's going to determine the number of APs you need as well. 00:06:16.320 --> 00:06:19.680 How far will people be sitting from an AP? 00:06:19.680 --> 00:06:20.680 Are they sitting here? 00:06:20.680 --> 00:06:21.680 Well then that's not good. 00:06:21.680 --> 00:06:23.600 They don't have enough coverage. 00:06:23.600 --> 00:06:29.180 They need to be closer or I need to add yet another AP to make sure that they have the 00:06:29.180 --> 00:06:31.120 coverage they need. 00:06:31.120 --> 00:06:37.760 Or even this, maybe the speeds are not enough. 00:06:37.760 --> 00:06:40.700 Remember our signal to noise ratio. 00:06:40.700 --> 00:06:46.920 Remember how we need a certain level of signal in order to make VoIP work. 00:06:46.920 --> 00:06:52.320 If I have a VoIP customer who's sitting here but they're only receiving a signal to noise 00:06:52.320 --> 00:06:59.400 ratio of 20 dB, is that going to work? 00:06:59.400 --> 00:07:00.400 Absolutely not. 00:07:00.400 --> 00:07:04.840 Remember I need a little bit of higher version of my signal to noise ratio. 00:07:04.840 --> 00:07:05.840 I need 25. 00:07:05.840 --> 00:07:13.640 So either I need to move this person in closer to the AP or I need to add another AP that 00:07:13.640 --> 00:07:16.640 makes them close enough for this to work. 00:07:16.640 --> 00:07:22.120 Focus on my drawing there for a second. 00:07:22.120 --> 00:07:26.360 So this is a very important aspect of wireless. 00:07:26.360 --> 00:07:32.160 You know a lot of people get away with wireless because they just keep throwing up APs without 00:07:32.160 --> 00:07:33.240 a plan. 00:07:33.240 --> 00:07:35.640 Don't be that administrator in your environment. 00:07:35.640 --> 00:07:38.580 Really take the time to plan it out and do it right. 00:07:38.580 --> 00:07:41.160 So that's all I have for this lesson. 00:07:41.160 --> 00:07:43.360 Very short and sweet but very important. 00:07:43.360 --> 00:07:47.000 This is the one that's going to determine the signal strength that your users are going 00:07:47.000 --> 00:07:48.000 to experience. 00:07:48.000 --> 00:07:49.600 So spend some time here. 00:07:49.600 --> 00:07:54.880 Make sure you understand everything we've done thus far has built upon the placement 00:07:54.880 --> 00:07:56.120 of these APs. 00:07:56.120 --> 00:08:02.680 It's now an easy topic to discuss but it relies on all that information we talked about before 00:08:02.680 --> 00:08:04.560 and a little bit of planning on your part. 00:08:04.560 --> 00:08:05.560 I'll see you in the next one. 00:08:05.560 --> 00:08:06.060 Bye for now.