Before app launch, developers usually need to optimize and verification app performance across diverse network conditions. For instance, after optimizing an app for smooth short video streaming during subway commutes, developers must verify whether stuttering issues have actually been resolved—but this requires testing in real-world scenarios.

Network Navigator, also known as netcopilot, provides comprehensive network simulation capabilities that enable developers to rapidly validate app user experience across typical network scenarios. This significantly improves testing efficiency and reduces verification costs. For example, developers can verify high-speed rail optimization effects without actually boarding a train.

In addition, NetCopeilot provides suggestions on data transmission optimization in these network scenarios. Your app can access Huawei Network Boost Kit to implement cross-layer collaboration between the app and the OS, improving the Internet access smoothness of the app.

For example, when transitioning between WLAN and mobile data networks while entering or exiting elevators, the app rapidly senses network interface changes and promptly redirects high-priority data requests to the new connection, ensuring seamless network switching without interruptions. When the network performance deteriorates, Network Boost Kit reports quality of service (QoS) data to assist the app in optimizing transmission scheduling.

Using Preset Network Simulation Scenarios

Network Navigator provides two access methods: the Settings interface and hdc command-line interface (CLI).

The following describes how to use NetCopilot through the settings screen. For details about how to use NetCopilot through the HDC command line, see NetCopilot Tool.

When you use this function for the first time, enable the developer mode on the device by referring to Enabling Developer Options. Then, go to Settings > System > Developer options > Network Pilot to access the Network Pilot screen.

Network Navigator has preset the following common network simulation scenarios. You can use them to quickly test app user experience.

How to Start a Network Simulation Scenario

To start network simulation, click any network simulation scenario you need from Available simulations. For example, after clicking In & out of elevator, the simulation scenario will be activated and you can view it in Active simulations.

You can also view the network simulation details in the device's live window.

How to Exit a Network Simulation Scenario

To stop a network simulation scenario, tap on the right and exit the simulation.

The following table lists the prerequisites and phases for the preset network simulation scenarios.

Network Simulation Scenario	Prerequisites	Scenario and Phase Description
In & out of elevator	Connect to WLAN and enable mobile data switch.	Simulates the scenario in which a user enters and exits elevator with network switching between WLAN and mobile network. This scenario consists of six phases, runs for 5 minutes total, and executes cyclically.
Leave home WLAN range	Connect to WLAN and enable mobile data switch.	Simulates the scenario in which a user leaves home, disconnecting from WLAN and switching to mobile network. This scenario consists of four phases, lasts for 3 minutes, and executes cyclically.
Enter home WLAN range	Connect to WLAN and enable mobile data switch.	Simulates the scenario in which a user moves from outdoor to indoor area, connecting to WLAN and disconnecting from mobile network. This scenario consists of three phases, lasts for 3 minutes, and executes cyclically.
Busy cafeteria	Connect to WLAN or mobile network.	Simulates a network with many connected devices, featuring high contention, low bandwidth, and high latency. This scenario consists of three phases, lasts for 5 minutes, and executes cyclically.
Parking	Connect to WLAN or mobile network.	Simulates a poor-quality network with weak signal, low bandwidth, and high latency. This scenario consists of three phases, lasts for 5 minutes, and executes cyclically.
Riding the subway	Connect to WLAN or mobile network.	Simulates a network with varying conditions, with strong signal at stations, and weak signal between stations. This scenario consists of five phases, lasts for 5 minutes, and executes cyclically.
Riding high-speed train	Insert dual SIM cards and enable mobile data switch.	Simulates a network with varying conditions, with frequent switching between cell towers, and intermittent loss of service. This scenario consists of five phases, lasts for 10 minutes, and executes cyclically.
Highway driving	Connect to WLAN or mobile network.	Simulates a network with varying conditions, with strong signal in urban areas and weak signal in tunnels. This scenario consists of five phases, lasts for 5 minutes, and executes cyclically.

For more details about the phases and network conditions, see Appendix.

Configuring a Customized Network Simulation Scenario

If the preceding preset network simulation scenarios cannot meet your development requirements, you can click Add Customized Network Scenario at the bottom of the Network Navigator page to add the required network configuration.

The value ranges of the parameters are as follows. After you enter a value for a parameter, the unit is automatically added. The parameter configuration of the customized scenario will be applied to the default network during startup. You are advised to use this function when the network environment is stable.

Parameters and options	Value Range	Unit
Upstream bandwidth	100 - 500000	Kbps
Downlink bandwidth.	100 - 2000000	Kbps
UL Packet Loss Rate	0.0 - 20.0	%
DL Packet Loss Rate	0.0 - 20.0	%
Uplink latency	1 - 1000	ms
Downlink delay	1 - 1000	ms

Currently, custom scenarios are not supported by Network Boost Kit. If you want to simulate the registration of the callback in a network scenario, you can use the preset network simulation scenarios.

Network Optimization Recommendations

With Network Navigator, you can monitor network changes in real time through the live window. You can also click the live window to view network simulation details. In addition, you can view network parameters and network coding best practices by clicking the respective link in the window.

Code Optimization Recommendations

Network Navigator intelligently simulates network QoS changes when activating specified scenarios, helping developers quickly build target network environments. Through this feature, developers can proactively discover app compatibility issues in different network environments and perform targeted optimization based on the best practices in this section.

Code Optimization Scenarios

Currently, eight network simulation scenarios are supported. For details, see Appendix. The network characteristics can be classified into three types: network switching, network fluctuation, and poor network quality. The following table lists the scenario characteristics and code development suggestions.

Network Switching

Characteristics: When a device switches between network types (for example, WLAN and cellular) or switches SIM cards, it may experience IP address changes, forced TCP connection resets, and delays due to DNS re-resolution and handshake re-establishment.
Typical scenarios: Entering and leaving an elevator, disconnecting from WLAN when leaving home, and traveling on high-speed rail (switching between SIM cards).

Best practices: Detect network switches in a timely manner and re-establish connections, perform DNS resolution, and re-send any incomplete requests. Alternatively, use the HTTP module of Network Kit to initiate network requests. Network Kit incorporates the intelligent multi-network switching capability of the Tongtu network protocol stack, which automatically reroutes pending and ongoing requests to the active network during network switching. This effectively prevents request failures and service response delays in network switching scenarios. The sample code for sending HTTP requests using Network Kit is as follows:

// Import related modules.
import { http } from '@kit.NetworkKit';
import { BusinessError } from '@kit.BasicServicesKit';
// Each httpRequest corresponds to an HTTP request task and cannot be reused.
 let httpRequest = http.createHttp();
 httpRequest.request(
  //Specify the URL for the HTTP request. The URL can include parameters or not. Specify request parameters in extraData.
  "EXAMPLE_URL", (err: BusinessError, data: http.HttpResponse) => {
  if (!err) {
    // data.result carries the HTTP response. Parse the response based on service requirements.
    console.info('Result:' + JSON.stringify(data.result));
    // Call the destroy() method to release resources after HttpRequest is complete.
    httpRequest.destroy();
  } else {
    console.error('error:' + JSON.stringify(err));
    // Call the destroy() method to release resources after HttpRequest is complete.
    httpRequest.destroy();
  }
}
);

Network Fluctuation

Characteristics: Due to rapid fluctuations in signal strength (for example, during movement or high-speed travel), network performance can degrade sharply. This includes a significant reduction in bandwidth (from 50 Mbps to 1 Mbps), severe jitter in delay (RTT fluctuations exceeding 300%), and intermittent packet loss (0% to 5%).
Typical scenarios: Riding the subway or driving on highways.
Best practices:

Subscribe to netQuality events in Network Boost Kit to monitor network quality in real time and take appropriate measures.

// Import the connection namespace.
import { netQuality } from '@kit.NetworkBoostKit';
import { BusinessError } from '@kit.BasicServicesKit';
try {
  netQuality.on('netQosChange', (list: Array<netQuality.NetworkQos>) => {
    if (list.length > 0) {
      list.forEach((qos) => {
        // Callback information processing.
        console.info(`Uplink bandwidth of this data link type: ${JSON.stringify(qos.linkUpBandwidth)}.` );
        console.info(`Downlink bandwidth of this data link type: ${JSON.stringify(qos.linkDownBandwidth)}.` );
        // The app can detect the network quality in real time based on information such as the uplink and downlink bandwidths and adjust the request policy accordingly.
      });
    }
  });
 } catch (err) {
  console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
}

When network quality is good, prefetch potential subsequent requests, send them in advance, and cache the fetched resources. When these requests are actually triggered, resources can be loaded directly from the cache, enhancing response speed and reducing latency.

// Import the connection namespace.
import { rcp } from '@kit.RemoteCommunicationKit';
import { HashMap } from "@kit.ArkTS";
export class PrefetchingRcp {
  private session = rcp.createSession();
  private responsePrefetched: HashMap<string, rcp.Response> = new HashMap<string, rcp.Response>();
  public async prefetch(url: string) {
    const request = new rcp.Request(url);
    try {
      // Send a prefetch request.
      let response: rcp.Response = await this.session.fetch(request);
      // Cache the fetched resources.
      this.responsePrefetched.set(url, response);
      return Promise.resolve();
     } catch (reason) {
       console.error(`Rcp prefetch failed: ${reason.code}`);
       return Promise.reject();
    }
  }
}

When network quality is poor, reduce request frequency or data volume to avoid worsening network congestion.

Poor Network Quality

Characteristics: In signal shielding areas (such as underground parking lots) or high-density access environments (such as crowded cafeterias), the network consistently exhibits low bandwidth (<1 Mbps), high latency (>100 ms), and a high packet loss rate.
Typical scenarios: Crowded cafeterias and parking lots.

Best practices: Reduce request frequency and data volume promptly when the network is congested, and resume requests once the network recovers. Besides using netQosChange to assess network quality, you can also subscribe to network scenario detection events to directly identify network congestion or weak signals. Upon detection, reduce request frequency to avoid repeated requests that could worsen network congestion. The sample code is as follows:

// Import the connection namespace.
import { netQuality } from '@kit.NetworkBoostKit';
import { BusinessError } from '@kit.BasicServicesKit';
try {
  netQuality.on('netSceneChange', (list: Array<netQuality.NetworkScene>) => {
    if (list.length > 0) {
      list.forEach((sceneInfo) => {
        // Process the network scenario identification callback information.
        if (sceneInfo.scene == 'congestion') {
          // Service logic implemented upon network congestion
        }
        if (sceneInfo.scene == 'normal') {
          // Service logic implemented upon network recovery
        }
        if (sceneInfo.weakSignalPrediction) {
          // Service logic implemented upon detection of potential network deterioration via weak signal prediction
        }
      });
    }
  });
 } catch (err) {
  console.error('errCode: ' + (err as BusinessError).code + ', errMessage: ' + (err as BusinessError).message);
}

Information Collection

When you use Network Navigator, your app usage records will be collected. We may contact you through the contact information linked to your HUAWEI ID for user feedback surveys, to help us further optimize this feature.

The data that will be collected includes:

Usage logs. You need to associate your HUAWEI ID to use Network Navigator. By enabling User Experience Improvement Program, you are automatically consenting to upload usage logs.
Bundle name and version number of the app that uses this feature.
Network simulation scenarios used by the app and the corresponding timestamps during usage.

Appendix

QoS in Different Network Scenarios

In & out of elevator

This scenario lasts for 5 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
Waiting for the elevator	0-30s	WLAN	60-140Mbps	random	30-60Mbps	random	0-20ms	random	0.00%-0.01%	random
Entering an elevator	30-90s	WLAN	90-50Mbps	linearDecrease	30-8Mbps	linearDecrease	2-20ms	linearIncrease	0.00%-0.21%	random
Elevator door closing	90-100s	WLAN	1-0Mbps	random	1-0Mbps	random	0-200ms	random	0.00%-0.00%	random
Elevator door closing	100-110s	WLAN	1-0Mbps	linearDecrease	1-0Mbps	linearDecrease	200-1000ms	linearIncrease	0.00%-8.00%	linearIncrease
Elevator door closing	110-120s	Cellular	20-50Mbps	random	5-15Mbps	random	0-20ms	random	0.00%-0.20%	random
Elevator going up	120-180s	Cellular	20-50Mbps	random	5-15Mbps	random	0-30ms	random	0.01%-0.20%	random
Elevator door opening	180-210s	Cellular	30-100Mbps	linearIncrease	15-50Mbps	linearIncrease	30-0ms	linearDecrease	0.01%-0.10%	random
Exiting elevator	210-240s	Cellular	100-300Mbps	linearIncrease	50-100Mbps	linearIncrease	0-10ms	random	0.00%-0.01%	random
Exiting elevator	240-300s	WLAN	60-140Mbps	random	30-60Mbps	random	10-20ms	random	0.00%-0.01%	random

Leave home WLAN range

This scenario lasts for 3 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
At home	0-60s	WLAN	60-140Mbps	random	30-60Mbps	random	0-15ms	random	0.00%-0.00%	random
At the door	60-90s	WLAN	100-50Mbps	linearDecrease	40-10Mbps	linearDecrease	5-15ms	linearIncrease	0.00%-0.00%	random
Walking away	90-110s	WLAN	5-0Mbps	random	5-0Mbps	random	0-200ms	random	0.00%-0.00%	random
Walking away	110-120s	WLAN	5-0Mbps	linearDecrease	5-0Mbps	linearDecrease	200-1000ms	linearIncrease	0.00%-8.00%	linearIncrease
Walking away	120-150s	Cellular	200-400Mbps	random	30-70Mbps	random	0-35ms	random	0.00%-0.00%	random
On a footpath	150-180s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random

Enter home WLAN range

This scenario lasts for 3 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
In the hallway	0-60s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random
At the door	60-90s	Cellular	200-400Mbps	random	30-70Mbps	random	0-35ms	random	0.00%-0.00%	random
At the door	90-120s	WLAN	30-50Mbps	random	10-30Mbps	random	10-40ms	random	0.00%-0.00%	random
Entering home	120-180s	WLAN	60-140Mbps	random	30-60Mbps	random	0-20ms	random	0.00%-0.00%	random

Busy cafeteria

This scenario lasts for 5 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
Entering cafeteria	0-60s	WLAN	60-140Mbps	random	30-60Mbps	random	0-20ms	random	0.00%-0.00%	random
Queuing for food	60-120s	WLAN	0-5Mbps	random	0-5Mbps	random	10-100ms	random	0.00%-2.4%	random
Sitting down to eat	120-240s	WLAN	15-60Mbps	random	10-20Mbps	random	0-55ms	random	0.00%-0.2%	random
Leaving cafeteria	240-300s	WLAN	60-140Mbps	random	30-60Mbps	random	0-20ms	random	0.00%-0.00%	random

Parking lot with weak signals

This scenario lasts for 5 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
Heading to the parking garage	0-60s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random
In a parking garage	60-240s	Cellular	0-10Mbps	random	0-10Mbps	random	30-100ms	random	0.00%-0.50%	random
Exiting parking garage	240-300s	Cellular	300-500Mbps	random	50-100Mbps	random	0-35ms	random	0.00%-0.00%	random

Riding the subway

This scenario lasts for 5 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
Waiting for the train at the subway platform	0-30s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random
Train is moving	30-150s	Cellular	0-10Mbps	random	0-10Mbps	random	0-35ms	random	0.00%-0.50%	random
The train has entered the station	150-180s	Cellular	300-500Mbps	random	50-100Mbps	random	0-35ms	random	0.00%-0.00%	random
Train is moving	180-270s	Cellular	0-10Mbps	random	0-10Mbps	random	0-35ms	random	0.00%-0.50%	random
The train has entered the station	270-300s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random

Riding high-speed train

This scenario lasts for 10 minutes and executes cyclically.

Sub-phase	Duration (min:sec)	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
Waiting at a high-speed railway platform	0-60s	Cellular (SIM 1)	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random
The train runs on the outskirts of the city	60-120s	Cellular (SIM 1)	100-250Mbps	random	20-50Mbps	random	0-35ms	random	0.00%-0.50%	random
The train is traveling in a mountainous area	120-240s	Cellular (SIM 1)	0-8Mbps	random	0-8Mbps	random	300-2000ms	random	0.00%-5.00%	random
The train is traveling in a mountainous area	240-360s	Cellular (SIM 2)	30-50Mbps	random	10-30Mbps	random	300-2000ms	random	0.00%-5.00%	random
The train has arrived at the station on the outskirts of a city	360-480s	Cellular (SIM 1)	200-400Mbps	random	30-70Mbps	random	0-35ms	random	0.00%-0.50%	random
Exiting the train station	480-600s	Cellular (SIM 1)	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random

Highway driving

This scenario lasts for 5 minutes and executes cyclically.

Sub-phase	Duration	Network interface.	Downlink bandwidth.	Downlink Bandwidth Distribution	Upstream bandwidth	Uplink Bandwidth Distribution	Latency	Delay Distribution	Packet loss	Packet Loss Distribution
Vehicle traveling in an urban area	0-60s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random
Vehicle entering a tunnel	60-120s	Cellular	0-2Mbps	random	0-2Mbps	random	300-2000ms	random	0.00%-5.00%	random
Vehicle traveling in an urban area	120-180s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random
Driving on the elevated road	180-240s	Cellular	0-10Mbps	random	0-10Mbps	random	0-35ms	random	0.00%-0.00%	random
Vehicle traveling in an urban area	240-300s	Cellular	300-500Mbps	random	50-100Mbps	random	0-25ms	random	0.00%-0.00%	random

目录

Getting Started with Network Navigator

Overview

Using Preset Network Simulation Scenarios

Configuring a Customized Network Simulation Scenario

Network Optimization Recommendations

Code Optimization Recommendations

Information Collection

Appendix