System Planning OpenStage WL 3 / OpenStage WL3 Plus Planning Guide A31003-M2000-P102-2-76A9
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Contents 3 Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Introduction to Wireless Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Adding Voice to a Wireless LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents AP Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Regulatory Domains - 802.11d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Transmission Data Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Short/Long Radio Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Beacon Period.
Introduction 5 Introduction This document is intended as a guide for considerations on WLAN infrastructure planning and installation to obtain maximum performance with respect to voice quality. The document handles the RF aspects in the 2.4 GHz and 5 GHz band of a multi-cell WLAN system with a focus on Access Point (AP) placement.
General General Introduction to Wireless Planning Adding Voice to a Wireless LAN Data and voice traffic has different characteristics and thus put different requirements on the design of the WLAN network. Data clients, like a laptop set up to use its wireless card for browsing the Internet, tries to use the max packet size that is allowed to transport the relative high amount of data that modern web pages contain.
General 7 A WLAN network can either operate on the IEEE 802.11 2.4 GHz (b/g) or a 5 GHz (a) band. Depending on the WLAN APs used, a network may support either one of those bands or both if the AP is equipped with dual radios. In such a case, the WLAN network can be thought of as two independent WLANs which are physically separated by the usage of different frequencies.
General Thus, if using separate VLANs for voice and data devices, for example having a voice VLAN with a Unite messaging server, there must be a route for the managing traffic coming from the data network to the device and also for sending messages from a data device (PC) to the Unite messaging server. NOTE: : Do not implement VLAN without having a clear understanding of which devices that need to talk with each other.
General 9 Combination of Data and Voice Channel Assignments The handset supports both a and b/g, and it is recommended to have the data and voice traffic on different bands, but not necessary have data on the -a band. Depending on the existing data and/or voice network, and choice of new installation preferences, the WLAN can be set up as follows, see tables below: Legacy Network Not Using Any 802.11n APs b/g a Comment Customer is running single radio APs.
General b/g Data (b/g) Voice (g) a Voice Data Comment If the WLAN contains of a lot of b/g data clients, it can be preferable to keep them in the 2.4 GHz band and have all voice clients use the 5 GHz band. The same planning considerations apply if DFS-channels not are used. This allows the 2.4 GHz band to be dedicated to voice and all data clients, if possible, are moved to the a-band. Customer Is Adding 802.
General 11 Customer buys new APs for the a/n-radio only and keeps the old single-radio b/g APs intact. New APs set to use only the a-radio. High throughput (HT) only in Greenfield mode. b/g old AP Voice + data (legacy) a new AP Data (HT) Comment This may be a solution when upgrading to 802.11n. 20 MHz only 40 GHz only All laptops can then benefit from the HT speeds of the a/n radio, and the higher amount of channels to choose from. Non-HT clients like handsets stay on the old APs.
General Customer buys new APs for the n-radio and keeps the old a/b/g APs intact. Running dual 5.0 GHz radios b/g - a New AP Data (HT) DFS Old AP Data (legacy) 20 MHz only Old AP Voice -(no HT),nonDFS, 20 MHz only. Comment This will allow the voice traffic to run on the non-DFS (Dynamic Frequency Selection) channels and the data traffic to run on the DFS channels. See also, Section , “802.11a Radar Protection, Dynamic Frequency Selection (DFS)”, on page -13. Customer Has Already Invested in 802.
General 13 b/g/n Legacy data a/n Voice 20 MHz Data 20 MHz Comment Note: Greenfield mode is not supported in the handset. or 40 MHz Greenfield mode 802.11 a-radio Support in the Handset 802.11a Radar Protection, Dynamic Frequency Selection (DFS) Several of the radio channels (the DFS-channels) available in the 5 GHz band are also used by a multitude of radars both for civilian and military purposes; for an example in aviation, weather radars.
General * For the FCC regulatory domain US and others countries the following rules apply for the UNII-2e band: - Devices will not transmit on channels which overlap the 5600 - 5650 MHz band (Ch 120, 124 and 128). - For outdoor use any installation of either a master or a client device within 35 km of a Terminal Doppler Weather Radar (TDWR) location shall be separated by at least 30 MHz (center-to-center) from the TDWR operating frequency.
General 15 The MIMO features require more than one radio channel and antennas, which will consume more power and hardware space in the handset. Double sized channel (40MHz) support reduces the amount of channels to half which makes channel planning much more difficult. Using short guide interval (SGI) makes a client more sensitive to interference and may not benefit a moveable client like a handset. Using 802.
Wired LAN/Backbone Requirements Battery Lifetime Since the number of charging cycles needed are dependent on the power consumption, the lifetime of the battery is highly dependent of the settings used. A poor network setup with no power save functionality will decrease the lifetime dramatically.
Wired LAN/Backbone Requirements 17 IEEE 802.11 Priority Field The 802.11 User Priority is sent using the 2 bit QoS Control Field in the 802.11 MAC header. IEEE 802.1q Priority Field. The structure of the VLAN Tag defined in 802.1Q is illustrated in the Figure 1. Figure 1. VLAN Identifier (VID) Prirority Mark 8 7 6 5 4 3 2 1 Octets 1 8 7 6 5 4 3 2 1 2 Figure 1 002 = 1 Bit Structure of a VLAN Tag. NOTE: The use of the 802.
Security Considerations Downlink to Wired Network The AP will preserve the 802.1D user priority by copying the value into the 802.1p priority tag. The IP DSCP value will be unaffected by the transition to the wired network. NOTE: The 802.1p priority tag is likely not preserved if VLANs are not configured throughout the wired network. If the packets will travel across different subnets, the router configuration needs to cope with preservation of the 802.1p priority tag.
Basic Cell Planning 19 For handover times with different security settings on particular WLAN infrastructure, see the appropriate configuration notes in respective VoWiFi configuration manual. The following security functions are not recommended: • WEP is not recommended. • Shared key authentication should be avoided since this authentication scheme makes it easier to crack the encryption key.
Basic Cell Planning The 5 GHz band consists of several sets of channels listed in the table below. See also Section , “802.11a Radar Protection, Dynamic Frequency Selection (DFS)”, on page -13. Radio 2.4GHz, 802.11b/g/n 20MHz 5GHz, 802.11a/n 20MHz 2.4GHz, 802.11n 40MHz 5GHz, 802.11n 40MHz ETSI 3 4 + 15 (DFS) 2 2 + 7 (DFS) FCC 3 9 + 12 (DFS) 1 4 + 5 (DFS) NOTE: The handset supports, but does not make use of, 40 MHz channel bonding.
Basic Cell Planning 21 The recommendations above ensure a fading margin of approximately 20dB which should be appropriate for “normal” environments. NOTE: The illustration in Figure 3 is valid when all APs’ transmission power are configured to 100mW (20dBm). Since the handset transmission power is pre-configured to approximately 100 mW, this ensures a symmetric wireless link.
Co-Channel Interference Figure 4. b/g Material Concrete Brick Wall Dry Wall Window Elevator Shaft Thin Door Book Shelf Plasterboard wall Attenuation 12 dB 10 dB 5 dB 1 dB 30 dB 2 dB 2 dB 3 dB NOTE: The attenuation for the -a radio is, from a general point of view, higher than for -b/g. Multipath Propagation 802.
Co-Channel Interference 23 There are 19 channels available in total in Europe and 24 in the USA (FCC channels), whereof there are four non-DFS in Europe and nine non-DFS in the USA. Data traffic only can use DFS channels, but it is not recommended for voice, since handsets can not use active scanning due to DFS regulations. NOTE: The handset can use the DFS channels, but the Voice quality may be distorted.
AP Placement for Optimal Performance Handset a/b/g If the handset detects an energy level that is stronger then -70 dBm or confirmed 802.11 traffic it will consider the air as occupied and not transmit. For example, if it hears an AP with -80 dBm and can identify it as 802.11 traffic, it will not transmit. A non 802.11 disturbance at -72 dBm will, however, not stop the handset from transmitting.
AP Placement for Optimal Performance 25 The AP distance to avoid co-channel interference is described in Section , “Clear Channel Assessment, CCA”, on page -23. The CCA will not introduce any transmission interrupts if the APs or STAs are separated to -76 dBm. However, if two APs on the same channel are transmitting at the same time, the handset will require the interfering signal to be attenuated at least 15 dB compared to their “own” signal.
Infrastructure Dependant Features Figure 8. Figure 7 It is recommended to place an AP in the middle of the walking path to reduce roaming between APs in separate rooms. Infrastructure Dependant Features Automatic RF Adaptations in WLAN Systems Many WLAN infrastructures make use of an internal tool that is changing the AP channels and/or transmit power level in a dynamic way.
Tools in the Handset 27 Unfortunately, IEEE 802.11 does not provide any procedure for a smooth transition of stations between APs. Instead, the move is done by deauthenticating the station until it associates to another AP. This forced transition will cause a loss of speech frames, and in worst case the call will be disconnected. Tools in the Handset There are a number of tools present in the handset to assist in verification of a WLAN system deployment.
AP Configuration MCS Index Data Rates Mbps 20 MHz Channel 1 13 2 19.5 3 26 4 39 5 52 6 58.5 7 65 Short/Long Radio Preamble This only affects the transmissions at 802.11b speeds. The use of short preamble reduces the time spent on the preamble considerably. Only old 802.11b equipment uses long preamble and should not be present on a high performing VoWiFi system. The 5 GHz band uses a preamble but there is no option to use short or long.
AP Configuration 29 Transmission Power By default the handset adapts its output power to the APs, but the output power can be configured in five steps between 0-20 dBm as well. Make sure that the APs and clients are configured to use the same output power to avoid asymmetric communication link budgets. The use of anything else in the APs creates an asymmetric communication link budget and is not recommended.
AP Configuration a/n Item Radio Transmitting power Recommended Settings 802.11a Set to match desired cell size. Radio channel UNII-1, UNII-3 Regulatory domain (802.11d) Beacon period Enabled DTIM interval 5 100 ms* Antenna diversi- Enable ty * Description The transmission rate will be up to 65 Mbps. If the output power is reduced make sure the APs and clients are configured to use the same output power to avoid asymmetric communication link budgets.
Known Problems 31 0.0.1 Quality of Service Item WMM * Recommended Settings Enable* Description Disabled QoS may work but there will be no guarantee for high voice quality. For the specific infrastructure, see the Interoperability Report. Identifier Item SSID Recommended Settings Max. 32 char Broadcast SSID Enable Description A unique identifier which stations use to associate with the AP.
Abbreviations and Glossary If the wired network contains a lot of APs connected to the same switch or if wireless traffic has to be route to a common device like a WLAN controller on the wired LAN, the switch itself or the common device may become a bottleneck. Abbreviations and Glossary Figure 9. 802.11a IEEE 802.11 standard for transmission rate of up to 54Mbps, operates in the 5GHz spectrum. 802.11b IEEE 802.11 standard for transmission rate of up to 11Mbps, operates in the 2.4GHz spectrum. 802.
Abbreviations and Glossary Greenfield mode IEEE IP MAC MIMO Multipath OTA PEAP MSCHAP PoE QoS RF RFID RSSI RTP SGI SISO SNR SSID STA TCP TLS TOS TSpec UDP UP VLAN VoWiFi WEP Wi-Di Wi-Fi Wi-Fi Direct PDM 33 A pure high throughput (HT) mode where packets are transmitted without a legacy-compatible part. Institute of Electrical and Electronics Engineers Internet Protocol: global standard that defines how to send data from one device to another over the wired and wireless media.
Abbreviations and Glossary WLAN WMM™ WSG WPA2™ ZigBee Wireless Local Area Network (LAN): A type of LAN in which data is sent and received via high-frequency radio waves rather than cables or wires. Wi-Fi Multimedia™: Offers QoS functionality for WiFi networks. Wireless Service Gateway: a module that enables wireless services to and from the WiFi Handsets in a WLAN system. It also includes the Device Manager. Wi-Fi Protected Access™: A set of security features for wireless networks based on IEEE 802.
