ZEBRA TC51 Mobile Computers User Guide

TC51, TC56,
TC70X, TC75X,
MC33 Best Practices Guide
Voice Deployment Optimization for
Extreme InfrastructureMN-004339-01EN Rev A

Copyright
ZEBRA and the stylized Zebra head are trademarks of Zebra Technologies Corporation, registered in many jurisdictions worldwide. All other trademarks are the property of their respective owners. ©2021 Zebra
Technologies Corporation and/or its affiliates. All rights reserved. Information in this document is subject to change without notice. The software described in this document is furnished under a license agreement or nondisclosure agreement. The software may be used or copied only in accordance with the terms of those agreements.
For further information regarding legal and proprietary statements, please go to:
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END USER LICENSE AGREEMENT: zebra.com/eula.

Terms of Use

Proprietary Statement
This manual contains proprietary information of Zebra Technologies Corporation and its subsidiaries (“Zebra Technologies”). It is intended solely for the information and use of parties operating and maintaining the equipment described herein. Such proprietary information may not be used, reproduced, or disclosed to any other parties for any other purpose without the express, written permission of Zebra Technologies.
Product Improvements
Continuous improvement of products is a policy of Zebra Technologies. All specifications and designs are subject to change without notice.
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Zebra Technologies takes steps to ensure that its published Engineering specifications and manuals are correct; however, errors do occur. Zebra Technologies reserves the right to correct any such errors and disclaims liability resulting therefrom.
Limitation of Liability
In no event shall Zebra Technologies or anyone else involved in the creation, production, or delivery of the accompanying product (including hardware and software) be liable for any damages whatsoever (including, without limitation, consequential damages including loss of business profits, business interruption, or loss of business information) arising out of the use of, the results of use of, or inability to use such product, even if Zebra Technologies has been advised of the possibility of such damages. Some jurisdictions do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.

About This Guide

This guide provides recommendations for voice deployment using the following mobile computers and their accessories.

• TC51
• TC51-HC
• TC56
• TC70x
• TC75x
• MC33.

Notational Conventions
The following conventions are used in this document:

• Bold text is used to highlight the following:
• Dialog box, window, and screen names
• Drop-down list and list box names
• Checkbox and radio button names
• Icons on a screen
• Key names on a keypad
• Button names on a screen
• Bullets (•) indicate:
• Action items
• List of alternatives
• Lists of required steps that are not necessarily sequential.
• Sequential lists (for example, those that describe step-by-step procedures) appear as numbered lists.

Icon Conventions
The documentation set is designed to give the reader more visual clues. The following graphic icons are used throughout the documentation set. These icons and their associated meanings are described below.
NOTE: The text here indicates information that is supplemental for the user to know and that is not required to complete a task.The text here indicates information that is important for the user to know.
Related Documents
For the latest version of this guide and all documentation sets for the respective devices, go to: zebra.com/ support.
Refer to specific vendor documentation for detailed infrastructure information.

Device Settings

This chapter includes device settings for default, supported, and voice traffic recommendations.
Default, Supported, and Recommended for Voice Device Settings
This section includes specific recommendations for voice that are not set as the default out-of-the-box configuration. It is generally advised to examine those specific settings in alignment with the WLAN network needs and compatibilities. In some cases, changing the defaults could harm generic connectivity performance.
Besides those specific recommendations which would need careful examination, most of the device’s default settings are already optimized for voice connectivity. For that reason, it is recommended to keep the defaults and let the device dynamically adjust the WLAN network dynamic feature-selection levels.
Device configuration should change only if there are WLAN network (wireless LAN controller (WLC), access points (AP)) features that mandate respective changes on the device side to allow proper inter-operation.
Note the following:

• Pairwise master key identifier (PMKID) is disabled on the device by default. If your infrastructure configuration is configured for PMKID, enable PMKID and disable the opportunistic key caching (OKC) configuration.
• The Subnet Roam feature allows you to change the network IP of the WLAN interface when the network is configured for a different subnet on the same extended service set identification (ESSID).
• In execution of default fast transition (FT) (also known as FT Over-the-Air), in case that other non-FT Fast Roaming Methods might be available on the same SSID, see Fast Roam Methods in Table 5 and relevant notes in General WLAN Recommendations on page 13.
• Use mobile device management (MDM) agents to change settings. Use the user interface (UI) to change parameter subsets.
• For voice applications, and for any highly-dependent client-server communication apps, it is not recommended to use the Android battery optimization feature (also known as Doze Mode) in device management tools. Battery optimization interrupts communication between dependent endpoints and servers.

Device Settings

The following table lists the default, supported, and recommended voice settings.
Table 1    Default, Supported, and Recommended Voice Device Settings

Feature| Default Configuration| Supported Configuration| Recommended for Voice
---|---|---|---
State11d| Country selection set to Auto| • Country selection set to Auto
• Country selection set to Manual| Default
ChannelMask_2.4 GHz| All channels enabled, subject to local
regulatory rules.| Any individual channel can be enabled or disabled, subject to local regulatory rules.| Device Mask matches the exact set of network side operating channels configuration. It is recommended to configure both the device and the network to a reduced set of channels 1, 6, and 11, if WLAN SSID is enabled on 2.4 GHz.
ChannelMask_5.0 GHz| All non-dynamic frequency selection
(DFS) channels enabled, subject to
local regulatory rules.| Any individual channel can be enabled or disabled, subject to local regulatory rules.| Device Mask matches the exact set of network side operating channels configuration. It is recommended to configure both the device and the network to a reduced set of only non-DFS channels. For example, in North America, configure the network channels to 36, 40, 44, 48, 149, 153, 157, 161, 165.
Band Selection| Auto (both 2.4 GHz and 5 GHz bands
enabled)| Any individual channel can be enabled or disabled, subject to local regulatory rules.| Device Mask matches the exact set of network side operating channels configuration. It is recommended to configure both the device and the network to a reduced set of only non-DFS channels. For example, in North America, configure the network channels to 36, 40, 44, 48, 149, 153, 157, 161, 165.
Band Preference| Disabled| • Auto (both bands enabled)
• 2.4 GHz
• 5 GHz| 5 GHz
Open Network Notification| Disabled| • Enable for 5 GHz
• Enable for 2.4 GHz
• Disable| Enable for 5 GHz, if WLAN SSID is on both bands.
Advanced Logging| Disabled| • Enable
• Disable| Default
User Type| Non-Restricted| • Enable
• Disable| Default
FT| Enabled| • Enable
• Disable| Default
OKC| Enabled| • Enable
• Disable| Default
PMKID| Disabled| • Enable
• Disable| Default
Feature| Default Configuration| Supported Configuration| Recommended for Voice
---|---|---|---
Power Save| NDP (Null data power save)| •NDP
•Power save polling (PS-POLL)
•Wi-Fi multimedia power save (WMM-PS)| Default
11k| Enabled| •Enable
•Disable| Default
Subnet Roam| Disabled| •Enable
•Disable| Default
11w| Disabled| •Enable / Mandatory
•Enable / Optional
•Disable| Default or
Enable / Optional
Channel Width| 2.4 GHz – 20 MHz
5 GHz – 20 MHz, 40 MHz and 80 MHz| Not configurable| Default
FT Over The DS| Enabled| •Enable
•Disable| Default
lln| Enabled| •Enable
•Disable
Note: Disabling this also disables 11ac.| Default
11ac| Enabled| •Enable
•Disable| Default
11v| Disabled| •Enable
•Disable| Enable

Device Wi-Fi Quality of Service (QoS) Tagging and Mapping
This section describes device QoS tagging and mapping of packets from the device to the AP (such as outgoing packets in the uplink direction).
The tagging and mapping of traffic in the downlink direction from the AP to the device is determined by the AP or controller vendor implementation or configuration, which is not in the scope of this document.
For the uplink direction, an application on the device sets Differentiated Service Code Point (DSCP) or Type of Service (ToS) values for its sourced packets, based on the application’s specifications. Prior to the transmission of each packet over Wi-Fi, the DSCP or ToS values determine the device’s further 802.11 Tagging ID assigned to the packet, and the mapping of the packet to 802.11 Access Category. The 802.11 tagging and mapping columns are provided for reference and are not configurable. The IP DSCP or ToS values may or may not be configurable, depending on the app.
NOTE: Table 2 describes the tagging and mapping values for outgoing packets when no other dynamic protocols affect them by standard specifications. For example, if the WLAN infrastructure mandates the Call Admission Control (CAC) protocol for certain traffic types (such as voice and/or signaling), tagging and mapping obey the dynamic states of the CAC specifications. This means that there could be CAC configuration or sub- periods in which the tagging and mapping apply different values than mentioned in the table, even though the DSCP value is the same.

IP DSCP Class Name| IP DSCP Value| ToS Hexa| Tagging of 802.11 TID (Traffic ID) and UP (802.1d UserPriority)| Mapping to 802.11 Access Category (same as Wi-Fi WMM AC spec)
---|---|---|---|---
none| 0| 0| 0| AC_BE
cs1| 8| 20| 1| AC_BK
af11| 10| 28| 1| AC_BK
af12| 12| 30| 1| AC_BK
af13| 14| 38| 1| AC_BK
cs2| 16| 40| 2| AC_BK
af21| 18| 48| 2| AC_BK
af22| 20| 50| 2| AC_BK
af23| 22| 58| 2| AC_BK
cs3| 24| 60| 4| AC_VI
af31| 26| 68| 4| AC_VI
af32| 28| 70| 3| AC_BE
af33| 30| 78| 3| AC_BE
cs4| 32| 80| 4| AC_VI
af41| 34| 88| 5| AC_VI
af42| 36| 90| 4| AC_VI
af43| 38| 98| 4| AC_VI
cs5| 40| A0| 5| AC_VI
ef| 46| B8| 6| AC_VO
cs6| 48| C0| 6| AC_VO
cs7| 56| E0| 6| AC_VO

Network Settings and Device RF Characteristics

Network Settings and Device RF Characteristics
This section describes device settings for the recommended environment and device RF characteristics.
Recommended Environment

• Perform a Voice Grade Site Survey to ensure the requirements in Table 3 are met.
• Signal to Noise Ratio (SNR), measured in dB, is the delta between the noise in dBm and the coverage RSSI in dBm. The minimum SNR value is shown in Table 3. Ideally, the raw noise floor should be -90 dBm or lower.
• In floor level, Same-Channel Separation refers to two or more APs with the same channel are in RF sight of a scanning device in a given location. Table 3 specifies the minimum received signal strength indicator (RSSI) delta between these APs.

Table 3 Network Recommendations

• No adjacent channels (overlapping)
• Overlapping APs must be on different channels 5 GHz: 36, 40, 44, 48, 149, 153, 157, 161, 165
• If you are using DFS channels, broadcast the SSID in beacons.
• Note: Unlicensed National Information Infrastructure-2 (U-NII-2) (DFS channels 52 to 140) and U-NII-3 (channels 149 to 165) are subject to the local regulatory rules

Device RF Capabilities
Table 4 lists the RF capabilities supported by the Zebra device. These are not configurable.
Table 4    RF Capabilities

• TC51-HC: 2×2 MIMO
• TC56: 1×1 SISO
• TC70x: 2×2 MIMO
• TC75x: 2×2 MIMO
• MC33: 2×2 MIMO
11n Capabilities| A-MPDU Tx/Rx, A-MSDU Rx, STBC, SGI 20/40 etc.
11ac Capabilities| Rx MCS 8-9 (256-QAM) and Rx A-MPDU of A-MSDU

Infrastructure and Vendor Model Recommendations

Infrastructure and Vendor Model Recommendations
This section includes recommendations for Extreme Networks infrastructure settings, including WLAN practices for enabling voice as well as more specific recommendations to manage voice traffic and maintain expected voice quality.
This section does not include a full list of WLAN configurations, but only those required verification, to accomplish successful interoperability between Zebra devices and the vendor-specific network.
The listed items may or may not be default settings of the given Extreme release version. Verification is advised.
General WLAN Recommendations
This section lists recommendations to optimize WLAN to support voice deployment.

• For best results, use Wi-Fi Certified (voice enterprise certification from Wi-Fi Alliance) AP models.
• If SSID for voice is enabled on 2.4G band, do not enable the 11b-legacy data rates on that band unless specifically required by some restricted coverage planning or older legacy devices must be supported.
• The device chooses to roam or connect to an AP depending on the infrastructure settings in effect and the underlying dynamics of the RF ecosystem. Generally, the device scans for other available APs at certain trigger points (for example, if the connected AP is weaker than -65 dBm) and connects to a stronger AP if available.
• 802.11r: Zebra strongly recommends that the WLAN network supports 11r Fast Transition (FT) as a fastroaming method to achieve the best WLAN and device performance and user experience.
• 11r is recommended above other fast-roaming methods.
• When the 11r is enabled on the network, either with pre-shared-key (PSK) security (such as FTPSK) or with an authentication server (such as FT-802.1x), the Zebra device automatically facilitates 11r, even if other parallel non-11r methods co-exist on the same SSID network. No configuration is needed.
• Disable unused Fast Roam Methods from the SSID if possible. However, if older devices on the same SSID support a different method, that two or more methods may remain enabled if they can coexist. The device automatically prioritizes its selection per the Fast Roaming Method in Table 5.
• It is a general best practice to limit the amount of SSID per AP to only those required. There is no specific recommendation on the number of SSIDs per AP as this depends on multiple RF environmental factors which are specific to each deployment. A high number of SSIDs impacts channel utilization which comprises not only users and application traffic, but also beacons traffic of all SSIDs on the channel, even those not in use.
• Call Admission Control (CAC):
• The network’s CAC feature is designed to facilitate VoIP deployments, but uses algorithmic complexities to determine whether to accept or reject new calls based on network resources in runtime.
• Do not enable (set to mandatory) CAC on the controller without testing and validating the stability of admissions (calls) in the environment under stress and plurality conditions.
• Be aware of devices that do not support CAC which are using the same SSID as Zebra devices support CAC. This scenario requires testing to determine how the network CAC impacts the entire eco-system.

WLAN Infrastructure Recommendations for Voice Support
Table 5    WLAN Infrastructure Recommendations for Voice Support

Note: Do not use Wired Equivalent Privacy (WEP) or Temporal Key Integrity Protocol (TKIP).
Authentication: Server Based (Radius)| 802.1X EAP-TLS/PEAP-MSCHAPv2
Authentication: Pre-Shared Key (PSK) Based| Enable both PSK and FT-PSK.
Note: Device automatically selects FT-PSK. PSK is necessary to support legacy /non-11r devices on same SSID.
Operational Data Rates| 2.4 GHz:
• G: 12, 18, 24, 36, 48, 54 (disable all lower rates, including 11blegacy)
• N: MCS 0 -15 5 GHz:
• A:12, 18, 24, 36, 48, 54 (disable all lower rates)
• AN: MCS 0 – 15
• AC: MCS 0 – 7, 8
Note: Adjust rate settings according to environmental characteristics.
See  Recommended Environment on page 11 to accomplish balanced AP minimum coverage.
Fast Roam Methods (See General WLAN Recommendations on page 13)| If supported by infrastructure in priority order:
• FT (802.11R)
• OKC or PMK Cache. Do not enable both.
DTIM Interval| 1
Beacon Interval| 100
Channel Width| 2.4 GHz: 20 MHz
5 GHz: 20 MHz
WMM| Enable
802.11k| Enable only Neighbor Report. Do not enable any 11k measurements.
802.11w| Enable as optional (not mandatory)
802.11v| Enable
AMPDU| Disable for voice.

Extreme Networks Infrastructure Recommendations for Voice Quality

Table 6    Extreme Networks Infrastructure Recommendations for Voice Quality

Recommendation| Required|

Recommended But Not Required

---|---|---
Configure voice WLAN to use the 802.11a band.| | ✓
If using EAP authentication, ensure that fast roaming is supported (for example, FT).| | ✓
Use the default WLAN QoS Policy settings.| ✓|
Set Bridging mode to Local.| ✓|
Disable Answer Broadcast Probes.| ✓|
Use the default Radio QoS Policy settings.| ✓|
Set Wireless Client Power to max.| ✓|

Zebra Recommended WLC and AP Firmware Versions
NOTE: Model versioning recommendations in this section are based on satisfactory interop test plan results. Zebra recommends that when using other software versions not listed below, consult the WLC/AP in the Release Notes to verify that a particular version is stable and preferred by the vendor.

• RFS 6K
• Software Version: 5.8.1.0
• RFS 7K
• Software Version: 5.8.0.0

Infrastructure and Vendor Model Recommendations

• NX9500
• Software version: 5.8.3.0
• AP Models: 650, 6532, 7522, 7532, 8131

www.zebra.com

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