1. 确保您的手机已连接到无线网络。

2. 打开手机上的浏览器。

3. 在浏览器地址栏输入路由器的默认IP地址，通常是“192.168.1.1”。

4. 按回车键后，您可能会看到一个登录窗口，要求您输入用户名和密码。默认的用户名和密码通常是“admin”。

5. 登录后， navigate to the "无线设置" section on the left sidebar of the router settings interface.

6. Click on "无线安全设置" within the wireless settings menu.

7. Select "WPA-PSK/WPA2-PSK" and then click on "PSK密码" to access the wireless password input field.

8. Enter the new wireless password and click "保存" at the bottom of the screen to save your changes.

9. After saving the new password, you will need to input the updated Wi-Fi password on your phone to reconnect to the network.

10. Expanding your wireless network involves two main methods: mobile data and Wi-Fi. Mobile data uses your phone's mobile network to access the internet, which can be costly and has a wide coverage area, allowing internet access almost anywhere you can make a phone call. Wi-Fi, on the other hand, has a smaller coverage area typically within 100 meters of the router. It requires connecting a wired network to a wireless router to transform it into a wireless signal. This Wi-Fi signal is then transmitted between your phone and the router.

11. Public places with wireless internet access, such as cafes or airports, typically use Wi-Fi technology. These networks may be password-protected or left open for anyone to use. In contrast, home wireless networks are private and require a password for access, which should be kept confidential to prevent unauthorized use and potential bandwidth theft.