Technical Bulletin. DIFFERENT OPERATING MODES, SPECTRAL BEHAVIOUR & DATA THROUGHPUT Prepared by: Jack Van der Star, P.Eng.

Transcription

1 DIFFERENT OPERATING MODES, SPECTRAL BEHAVIOUR & DATA THROUGHPUT Prepared by: Jack Van der Star, P.Eng. This technical bulletin provides observations of spectrum and data throughput behavior under different bandwidth operating modes, different path conditions and using different (Fast Frame, Packet Bursting, Compression, Dynamic Turbo & WMM) protocol extensions and their combinations. Measurements of simplex and duplex data throughputs were taken over paths in a lab environment and over 10 kilometers using both internal +19 dbi flat panel antenna and external +28dBi parabolic antennas. Using a laboratory link of 5.2 GHz, photos of occupied bandwidth on a spectrum analyzer set to peak hold with link settings of Quarter (5 MHz), Half (10 MHz), Full (20 MHz) and Dynamic Turbo (40 MHz) are shown in Figures 1.0 to 4.0. These illustrate that the occupied bandwidth expands out symmetrically from the centre frequency. An important observation is that the occupied bandwidth remained the same for wireless protocol enhancements individually or in any combination for Fast Frames, Packet Bursting, Compression and WMM. Photos of the 10 kilometer test link, equipment used and rf environment are provided in Figures 5.0 to 9.0 with detailed data throughput test results provided in Tables 1.0 & 2.0 and Figures 10.0 to Figure 1.0 Spectrum Using Quarter (5 MHz) Setting with 5.2 GHz Centre Frequency 1

2 Figure 2.0 Spectrum Using Half (10 MHz) Setting with 5.2 GHz Centre Frequency Figure 3.0 Spectrum Using Full (20 MHz) Setting with 5.2 GHz Centre Frequency 2

3 Figure 4.0 Spectrum Using Turbo (40 MHz) Setting with 5.2 GHz Centre Frequency Other observations in the use of these bandwidth options are: 1. There is no Dynamic Turbo mode available for the Quarter and Half settings since this is locked or greyed out in the Waveteq GUI. This prevents adjacent spectrum to be grabbed randomly thus improving spectrum management abilities. 2. Dynamic Turbo engages extra spectrum only when data is being transferred over the link. In this mode observations show that the extra 10MHz of spectrum was grabbed on each side of a full (20 MHz) carrier for a total bandwidth of 40MHz. 3. The use of any of the four enhancement modes or their combination of Fast Frames, Packet Bursting, Compression or/and WMM does not occupy any additional adjacent spectrum but does increase throughput more than twice in some cases in the Quarter and Half bandwidth modes. When data throughput approaches 20 Mbps these enhancements provide only marginal improvements. 3

4 Review of Different Operating Modes or Wireless Enhancements The ShadowMaster and ShadowAP have the following additional modes or wireless enhancements to improve link performance. These must be set the same for both radio interfaces that are used to create a link in order to pass data. Their selection can improve link performance significantly over a plain Wi-Fi interface. An explanation of each wireless enhancement available is described below and results of tests conducted across a laboratory and a 10 kilometer link using both a +19 dbi internal antenna and an external +28 dbi Parabolic Antenna are summarized in Table 1.0 & 2.0. Operating Modes or Wireless Enhancements: 1. Fast Frames: In wireless transmissions there is a lot of extra communication overhead to send each piece of data. Fast Frames will combine many smaller wireless packets to make one 'superpacket' to reduce the overall overhead of a wireless link, thereby improving the efficiency and the speed under certain operating conditions. This feature must be enabled and supported on both sides of the wireless connection in order to work properly. 2. Packet Bursting: Normally a wireless device has to wait for clearance between each transmission. By enabling this, the ShadowMaster will send a 'burst' of up to 3 data packets before waiting the required period. This feature must be enabled and supported on both sides of the wireless connection in order to work properly. 3. Compression: Rather than wasting the valuable bandwidth of the wireless link, the ShadowMaster can utilize compression techniques to reduce the amount of data that needs to be transmitted. This feature must be enabled and supported on both sides of the wireless connection in order to work properly. 4. Dynamic Turbo: Dynamic Turbo Mode utilizes adjacent channels in order to increase data rates. It dynamically adjusts based on the need and the interfering environment. This feature must be enabled and supported on both sides of the wireless connection in order to work properly. 5. WMM: Wi-Fi Multimedia (WMM) is based on the IEEE e standard. It provides basic quality of service (QoS) features to a Wi-Fi network by prioritizing traffic according to 'voice', 'video', 'best effort', and 'background' categories. WMM does not provide guaranteed throughput, but improves the performance of simple applications that require QoS, such as Wi-Fi Voice over IP (VoIP). Results Summary Results are shown in Table 1.0 for the most sprectrum efficient modes which are provided by selecting the options for Fast Frames, Packet Bursting, Compression and WMM in QUARTER, HALF and FULL Channel width options. WMM provides prioritization for mixed traffic and therefore improves service performance without taking extra frequency spectrum. DYNAMIC TURBO increases throughput (better in non-interfering conditions) by adding adjacent spectrum to do so. Table 1.0 & 2.0 shows the results of selecting individual options and their combinations. Note that the relevant screen images are shown in Figures 10.0 to 67.0 and are referenced in the Tables 1.0 &

5 WMM Compression Packet Bursting Fast Frames Technical Bulletin Table 1.0 Data Throughput Results in the LAB and Across a 10 Kilometer Wireless Link Using Internal +19 dbi Panel Antennas and External +28 dbi Parabolic Antenna TEST 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +17 dbi Internal Antennas 10 Kilometer Link Tests Using +17 dbi Internal Antennas Lab Tests Using +17 dbi Internal Antennas Lab Tests Using +17 dbi Internal Antennas Data Throughput 5 MHz (Quarter) 10 MHz (Half) 20 MHz (Full) 40 MHz (Dynamic Turbo) Simplex (Kbps) Duplex (Kbps) Screen Shot Figures 10.0 & & & & 27.0 x x x Simplex (Kbps) x x x Duplex (Kbps) Screen Shot Figures 12.0 & & & & 39.0 Simplex (Kbps) Duplex (Kbps) Screen Shot Figures 40 & & & 49 x x x x Simplex (Kbps) x x x x Duplex (Kbps) Screen Shot Figures 42 & & & 51 Simplex (Kbps) Duplex (Kbps) Screen Shot Figures 52 & & & & 65 x x x x Simplex (Kbps) x x x x Duplex (Kbps) Screen Shot Figures 54 & & & & 67 NOTE: Data throughput was measured across the link by utilizing a nepim throughput server which is established at one by using putty to enter the radio shell and issuing the command nepim to start the server (ctl C stops it). At the other end of the link (client end), log into the shell and issue the command nepim c [Server IP Address]. This will initiate the data throughput test with the number recorded in the table being the average value. The Duplex test is performed from the client side by issuing the command nepim c [Server IP Address] d 5

6 WMM Compression Packet Bursting Fast Frames Technical Bulletin Table 2.0 Individual Data Throughput Results Across a 10 Kilometer Wireless Link Using +28 dbi External Parabolic Antennas 1 1a 1b 1c 1d 1e 1f 1g INDIVIDUAL TEST 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas 10 Kilometer Link Tests Using +28 dbi Parabolic Antennas Data Throughput 20 MHz (Full) 40 MHz (Dynamic Turbo) Simplex (Kbps) Duplex (Kbps) Screen Shot Figures 18 & & 27 x x x x Simplex (Kbps) x x x x Duplex (Kbps) Screen Shot Figures 34 & & 37 x Simplex (Kbps) x Duplex (Kbps) Screen Shot Figures 20 & 21 x Simplex (Kbps) x Duplex (Kbps) Screen Shot Figures 22 & 23 x Simplex (Kbps) x Duplex (Kbps) Screen Shot Figures 24 & 25 x Simplex (Kbps) x Duplex (Kbps) Screen Shot Figures 28 & 29 x x Simplex (Kbps) x x Duplex (Kbps) Screen Shot Figures 30 & 31 x x x Simplex (Kbps) x x x Duplex (Kbps) Screen Shot Figures 32 & 33 6

7 10km Link Measurements Using +28 dbi Parabolic Antennas Measurements were undertaken over a 10 km link passing over water and in the presence of co-channel interference at the office end. Figure 5.0 & 6.0 show a spectrum surveys of known SSID s recognized by the receivers at each end of the link which were taken using the ShadowAP s site survey tool. Photos of the installations are also provided of the two communications sites in Figure 7.0 & 8.0. In the photographs please note the ShadowAP and the external 60cm parabolic antennas. End Equipment Configuration (10 km Test Link) Figure 5.0 Spectrum Survey at end showing Co-Channel CH 40 (5200 MHz) interference off the +28 dbi 60 cm Parabolic Antenna as being 4 db down from the ENTEL Test Signal 7

8 Figure 6.0 Photo of Equipment Installation at the End Showing the 10 Kilometer Path to the Parabolic Antenna at the Side(near end) from the Ski Club Site (far end). ShadowAP Under Test with +19 dbi Internal Antenna +28 dbi 60 cm External Parabolic Antenna 8

9 Ski Club End Equipment Configuration(10 km Test Link) Figure 7.0 Spectrum Survey at Ski Club end showing Co-Channel interference off the 60 cm +28 dbi Parabolic Antenna with no Interference on CH 52 (5200 MHz) 9

10 +28 dbi 60 cm Parabolic Antenna ShadowAP Under Test with +19 dbi Internal Antenna Figure 8.0 Equipment Configuration at the Ski Club Site Showing the +28 dbi Antenna, ShadowAP and the 10 Kilometer Path to the Waveteq Site 10

11 Figure Kilometer Test Path Over Water from Ski Club Looking Toward the Waveteq Communication Inc. with ShadowAP in Foreground 11

12 10 Kilometer Data Throughput Tests in the 5 MHz (QUARTER) Mode using +28dBi Parabolic Antennas Figure MHz (QUARTER) One Way Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna Figure MHz (QUARTER) Duplex Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna 12

13 Figure MHz (QUARTER) One Way Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna Figure MHz (QUARTER) Duplex Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna 13

14 10 Kilometer Data Throughput Tests in the 10 MHz (HALF) Mode Using +28 dbi Parabolic Antennas Figure MHz (HALF) One Way Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna Figure MHz (HALF) Duplex Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna 14

15 Figure MHz (HALF) One Way Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna Figure MHz (HALF) Duplex Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna NOTE: This mode selection appears to be one of the most spectrum efficient assuming sufficient link margin is available. 15

16 10 Kilometer Data Throughput Tests in the 20 MHz (FULL) Mode Using +28 dbi Parabolic Antennas Figure MHz (FULL) One Way Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna 16

17 Figure MHz (FULL) One Way Data Throughput Tests with Fast Frames option selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Fast Frames option selected using the +28 dbi Parabolic Antenna 17

18 Figure MHz (FULL) One Way Data Throughput Tests with Packet Bursting option selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Packet Bursting option selected using the +28 dbi Parabolic Antenna 18

19 Figure MHz (FULL) One Way Data Throughput Tests with Compression option selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Compression option selected using the +28 dbi Parabolic Antenna 19

20 Figure MHz (FULL) One Way Data Throughput Tests with Dynamic Turbo option selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Dynamic Turbo option selected using the +28 dbi Parabolic Antenna 20

21 Figure MHz (FULL) One Way Data Throughput Tests with WMM option selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with WMM option selected using the +28 dbi Parabolic Antenna 21

22 Figure MHz (FULL) One Way Data Throughput Tests with Fast Frames and Packet Bursting options selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Fast Frames and Packet Bursting options selected using the +28 dbi Parabolic Antenna 22

23 Figure MHz (FULL) One Way Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna 23

24 Figure MHz (FULL) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +28 dbi Parabolic Antenna Figure MHz (FULL) Duplex Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +28 dbi Parabolic Antenna 24

25 Figure MHz (DYNAMIC TURBO) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +28 dbi Parabolic Antenna Figure MHz (DYNAMIC TURBO) Duplex Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +28 dbi Parabolic Antenna 25

26 Figure MHz (DYNAMIC TURBO) One Way Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna Figure MHz (DYNAMIC TURBO) Duplex Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +28 dbi Parabolic Antenna 26

27 10 Kilometer Data Throughput Tests in the 5 MHz (QUARTER) Mode using +19dBi Flat Panel Internal ShadowAP Antennas Figure MHz (QUARTER) One Way Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna Figure MHz (QUARTER) Duplex Data Throughput Tests no enhancement option selected using the +28 dbi Parabolic Antenna 27

28 Figure MHz (QUARTER) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression & WMM options selected using the +19 dbi Internal Antennas. Figure MHz (QUARTER) Duplex Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal Antennas. 28

29 10 Kilometer Data Throughput Tests in the 10 MHz (HALF) Mode Using +19dBi Flat Panel Internal ShadowAP Antennas Figure MHz (HALF) One Way Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas Figure MHz (HALF) Duplex Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas 29

30 Figure MHz (HALF) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression & WMM options selected using the +19 dbi Internal ShadowAP Antennas Figure MHz (HALF) Duplex Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas 30

31 10 Kilometer Data Throughput Tests in the 20 MHz (FULL) Mode using +19dBi Flat Panel Internal ShadowAP Figure MHz (FULL) One Way Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas Figure MHz (FULL) Duplex Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas 31

32 Figure MHz (FULL) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas Figure MHz (FULL) Duplex Data Throughput Tests with with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas 32

33 LAB Data Throughput Tests in the 5 MHz (QUARTER) Mode using +19dBi Flat Panel Internal ShadowAP Antennas Desk Bench Figure MHz (QUARTER) One Way Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (QUARTER) Duplex Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas 33

34 Desk Bench Figure MHz (QUARTER) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (QUARTER) Duplex Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas 34

35 LAB Data Throughput Tests in the 10 MHz (HALF) Mode Using +19dBi Flat Panel Internal ShadowAP Antennas Desk Bench Figure MHz (HALF) One Way Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (HALF) Duplex Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas 35

36 Desk Bench Figure MHz (HALF) One Way Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (HALF) Duplex Data Throughput Tests with Fast Frames, Packet Bursting and Compression options selected using the +19 dbi Internal ShadowAP Antennas 36

37 LAB Data Throughput Tests in the 20 MHz (FULL) Mode using +19dBi Flat Panel Internal ShadowAP Desk Bench Figure MHz (FULL) One Way Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (FULL) Duplex Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas 37

38 Desk Bench Figure MHz (FULL) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (FULL) Duplex Data Throughput Tests with with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas 38

39 LAB Data Throughput Tests in the Dynamic Turbo Mode using +19dBi Flat Panel Internal ShadowAP Desk Bench Figure MHz (DYNAMIC TURBO) One Way Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (DYNAMIC TURBO) Data Throughput Tests no enhancement option selected using the +19 dbi Internal ShadowAP Antennas 39

40 Desk Bench Figure MHz (DYNAMIC TURBO) One Way Data Throughput Tests with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas Desk Bench Figure MHz (DYNAMIC TURBO) Data Throughput Tests with with Fast Frames, Packet Bursting, Compression and WMM options selected using the +19 dbi Internal ShadowAP Antennas 40