Does it Matter What AP You Buy?

Transcription

1 #WLPC Does it Matter What AP You Buy? Wes Technical Marketing Engineer, Cisco

2 Vendors Make Lots of APs 90APs (Controller Based APs) *Give or take a few*

3 Typical AP Portfolios Example 1 Good Better Best Example 2 Good More Good Better Best Example 3 Good More Good Better More Better Best #WLPC 3

4 Does it Matter What AP You Buy? Let s start with performance

5 Performance with an Old Client Across AP Generations Some Vendor 11n Client A Different Vendor 11n Client +5% +16% +39% +23% +13% +28% 11ac Wave 2 11ac Wave 1 11n Gen 2 11n Gen 1 11ac Wave 2 11ac Wave 1 11n Gen 2 11n Gen 1 20 MHz Channel 3ss 11n Client #WLPC 5

6 But Why? Each Generation Improves on the last (Usually) Better Radios Better CPUs Better Antennas Better AP AP1815i c AP1000 Series c #WLPC 6

7 Performance with Multiple Clients Across AP Generations Another Vendor Vendor Ocho 40 Clients 40 Clients +5% +39% +15% +31% +15% +33% 11ac Wave 2 11ac Wave 1 11n Gen 2 11n Gen 1 11ac Wave 2 11ac Wave 1 11n Gen 2 11n Gen 1 20 MHz Channel 2ss and 3ss 11ac W1 Clients #WLPC 7

8 How about Low End and High End APs?

9 100 Client Test A mixture of 100 clients representative of the real world 10x MacBook Pro 11n 10x ipad Air 11n 10x Dell E6430 w/ Broadcom ac 20x MacBook Pro 11ac 20x MacBook Air 11ac 30x Dell 6430 w/ Intel ac 70/30 Mix between 5 GHz and 2.4 GHz Clients were spread around the AP from 10 (3m) to 45 (13.7m)

10 100 Client Results Some Vendor Multi-Client Performance Multi-Client Performance A Different Vendor +28% +21% +19% Clients Clients Low End Wave 2 AP Mid Range Wave 2 High End Wave 2 AP Mid Range Wave 2 AP High End Wave 2 AP Low End Wave 2 AP

11 Some Low End APs have Client Scaling Issues Usually hardware limitation Inconsistent ping when too many clients are connected #WLPC 11

12 What about the RF?

13 APs Have Differing Numbers of Transceivers Transmitters Spatial Streams AP AP 4x4:4 Receivers Low End AP 2x2 High End AP 4x4

14 MRC Effect on Received Signal Maximal Ratio Combining Combined Effect (Adding all Rx Paths) 3 Antennas Rx Signals 14

15 Aligning of the Phases of MIMO Tx Signals to Maximize Signal at the Client is Beamforming 15

16 Beamforming as Swiss Cheese An extra transmitter is required to beamform effectively BRKEWN

17 3x3 vs. 4x4 100 Client Results Client TCP Down 12% 10% 4x4 offered a 3%-10% throughput improvement Throughput (Mbps) % 6% 4% 2% Percentage A 4x4 Cisco x4 Cisco x3 Percent Diff B A 3x3 B Clients 0% D C D C

18 But Why? (100 Client Test) Client Breakdown: 1/3 rd 3ss 2/3 rd 2ss 4x4 had a lower retry rate: 3x3: 10.5% 4x4: 7.3%

19 Data Rate Heat Map Recorded data rates to a 3ss client (MacBook Pro) at 41 locations in an office cubicle environment while passing traffic to the client The Environment

20 Data Rate Heat Map Downlink Data Rate Comparison Data Rate Modulation MCS (Mbps) 3x3 AP 4x4 AP 64QAM m % 0% 256QAM m % 15% 256QAM m % 85% 4x4 maintains 11ac rates throughout the entire area; and is able to maintain m9 at 85% of the locations The 3x3 heat map is almost 50% m7 Average data rate: 4x Mbps 3x Mbps ~15% Delta 4x4 AP 3x3 AP

21 4x4 Findings (Cliff Notes Version) Average of 2.4 db downlink RSSI improvement via Beamforming (vs. 3x3) Average of 1 db uplink RSSI improvement via MRC (vs. 3x3) Significant improvement in data rates (downlink and uplink) (15%), which equates to throughput gains, particularly in multi-client (~10%) Downlink Data Rate Comparison Data Rate Modulation MCS (Mbps) 3x3 AP 4x4 AP 64QAM m % 0% 256QAM m % 15% 256QAM m % 85% *Average improvements to a 3ss client

22 Notes on MRC and Beamforming More antennas gives more degrees of freedom Generally for beamforming to be effective an addition transmitter is required Most vendors have gone to 4x4 on their high end APs and support MRC and beamforming Clients must support beamforming (unless implicit beamforming technique in use) 11ac beamforming is in the standard and many clients actually use it in practice. Gains from Beamforming and MRC are most noticed in challenging RF environments #WLPC 22

23 Number of Transmitters Affects AP Tx Power Assume 17 dbm per path 1 Transmitter = 17 dbm Total Power 2 Transmitters = 20 dbm 3 Transmitters = 22 dbm 4 Transmitters = 23 dbm TPO = Per Path + 10*log(NumAnt) Example: 17 dbm + 10*log(4) = 23 dbm #WLPC 23

24 Mind the PoE Draw Older generation and lower end APs read fewer transmitters require less power Typically will operate on 802.3af 802.3at is a common requirement for full functionality on 11ac APs Some APs, particularly outdoor APs, and when USB in use require UPoE! #WLPC 24

25 Size and Weight #WLPC 25

26 Different Types of APs Wallplate AP Outdoor AP External Antennas AP #WLPC 26

27 What s the Bottom Line? Know your requirements Consider The RF Decide which AP is for you #WLPC 27

28 Thank you