ZEBRA TC77 Series Mobile Computers User Guide

: June 13, 2024
: ZEBRA

Table of Contents

About This Guide
Device Settings
Network Settings and Device RF Characteristics
Infrastructure and Vendor Model Recommendations
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ZEBRA TC77 Series Mobile Computers User Guide

About This Guide

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

TC52
TC52-HC
TC52x
TC57
TC72
TC77
PC20
MC93
EC30

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 interoperation.

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 14.
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.
Media access control (MAC) randomization:
- From Android Oreo onwards, Zebra devices support the MAC randomization feature, which is enabled by default. Disable or enable this via MDM or via Android privacy setting Use Device MAC:
- When enabled in Android 10 versions and earlier, the randomized MAC value is used only for Wi-Fi scanning of new networks prior to association with the intended network (prior to new connection), however, it is not used as the associated device MAC address. The associated MAC address is always the physical MAC address.
- When enabled in Android 11 onwards, the randomized MAC value is also used for association with the intended network. The randomized value is specific for each network name (SSID). It remains the same when the device roams from one AP of the connected network to different AP(s) of the same network, and/or when it has to fully re-connect to the specific network after being out of coverage.
- The MAC randomization feature does not affect voice performance and it is not necessary to disable this feature for general troubleshooting purposes. However, in some specific situations, disabling it may be helpful during the troubleshooting data collection

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
---|---|---|---
Auto Time Config| Disabled|

Enable (works only on Extreme infrastructure)
Disable

| Default
State11d| Country selection set to Auto|

Country selection set to Auto
Country selection set to Manual

| Default
Feature| Default Configuration| Supported Configuration| Recommended for Voice
---|---|---|---
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 thedevice 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| • Up to Android Oreo Build Number 01.13.20, all non- dynamic frequency selection(DFS) channels are enabled.• From Android Oreo Build Number01.18.02 onwards,Android 9 and,Android 10, all channels are enabled, including DFS.All the above are 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 thedevice 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)|

Auto (both bands enabled)
2.4 GHz
5 GHz

| 5 GHz
Band Preference| Disabled|

Enable for 5 GHz
Enable for 2.4 GHz
Disable

| Enable for 5 GHz, if WLAN SSID is on both bands.
Open Network Notification| Disabled|

Enable
Disable

| Default
Advanced Logging| Disabled|

Enable
Disable

| Default
Feature| Default Configuration| Supported Configuration| Recommended for Voice
---|---|---|---
User Type| Non-Restricted|

Enable
Disable

| Default
FT| Enabled|

Enable
Disable

| Default
OKC| Enabled|

Enable
Disable

| Default
PMKID| Disabled|

Enable
Disable

| Default
Power Save| NDP (Null data power save)|

NDP
Power Save PS-POLL
Wi-Fi multimedia power save (WMM-PS)

| Default
11k| Enabled|

Enable
Disable

| Default
Subnet Roam| Disabled|

Enable
Disable

| Default
11w| After Android 10: Enable / OptionalBefore Android 10: Disable|

Enable / Mandatory
Enable / Optional Disable

Enable
Disable
Note: Disabling this also disables 11ac.

| Default
11ac| Enabled|

Enable
Disable

| Default

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 CACspecifications. 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.

Table 2 Device Wi-Fi QoS Tagging and Mapping for Outgoing Traffic

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
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)
---|---|---|---|---
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

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

Setting	Value
Latency	< 100 msec end-to-end
Jitter	< 100 msec
Packet Loss	< 1%
Minimum AP Coverage	-65 dBm
Minimum SNR	25 dB
Minimum Same-Channel Separation	19 dB
Radio Channel Utilization	< 50%
Coverage Overlap	20% in critical environments
Setting	Value
---	---
Channel Plan

2.4 GHz: 1, 6, 11
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

Setting	Value
Roam Threshold	-65dbm (cannot be modified)
Device-specific Antenna Configuration	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

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.
If WPA3 is required for the deployment, refer to the Zebra WPA3 Integrator Guide for guidance on device models that support WPA3 and configuration guidance.

WLAN Infrastructure Recommendations for Voice Support

Table 5 WLAN Infrastructure Recommendations for Voice Support

Setting	Value
Infra type	Controller based
Security	WPA2 or WPA3
Voice WLAN	5 GHz only
Encryption	AESNote: 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 11b- legacy)
N: MCS 0 -155 GHz:
A:12, 18, 24, 36, 48, 54 (disable all lower rates)• AN: MCS 0 – 15
AC: MCS 0 – 7, 8Note: Adjust rate settings according to environmental characteristics. See Recommended Environment on page 12 to accomplish balanced AP minimum coverage.

Table 5 WLAN Infrastructure Recommendations for Voice Support (Continued)

Setting	Value
Fast Roam Methods (See General WLANRecommendations on page14)	If supported by

infrastructure in priority order:

FT (802.11R)
OKC or PMK Cache. Do not enable both.

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.