How do you support wireless network mobility and roaming using handover and seamless switching techniques?

1 What is handover and seamless switching?

Handover and seamless switching are two techniques that enable wireless devices to switch from one access point (AP) or network to another without losing connection or data. Handover is the process of transferring a device's association from one AP to another within the same network, while seamless switching is the process of moving a device from one network to another without noticeable interruption or re-authentication. Both techniques aim to provide continuous and smooth wireless service to users.

2 Why are handover and seamless switching important?

Handover and seamless switching are important for wireless network mobility and roaming because they allow users to move freely and access different resources and services without losing connectivity or quality of service. For example, handover can enable a user to walk around a building or campus and maintain a stable connection to the same network, while seamless switching can enable a user to switch from a Wi-Fi network to a cellular network or vice versa without noticing any delay or disruption. These techniques can also improve network performance, security, and efficiency by optimizing the use of available bandwidth and resources.

3 How do handover and seamless switching work?

Handover and seamless switching work by using various protocols and mechanisms to detect, select, and connect to the best available AP or network for a wireless device. Depending on the type and level of handover or switching, these protocols and mechanisms can involve different layers of the network stack, such as the physical, link, network, or application layer. For example, some common handover and switching techniques are layer 2 handover, which is the most basic type of handover where a device switches from one AP to another within the same network based on signal strength and quality; layer 3 handover, which is a more advanced type of handover where a device switches from one AP to another across different subnets or networks based on network layer information; vertical handover, which is a type of seamless switching where a device switches from one network to another with different technologies; and application layer seamless switching, which is a type of seamless switching where a device switches from one network to another with the same or different technologies based on application layer information. Each of these techniques requires various levels of cooperation and coordination between different layers of the network stack in order to ensure optimal user experience and satisfaction.

4 What are the challenges and limitations of handover and seamless switching?

Handover and seamless switching can be challenging in real-world scenarios, often leading to latency and packet loss, security and privacy risks, compatibility and interoperability problems, as well as cost and complexity issues. Latency and packet loss can affect the quality of service and user experience, especially for real-time applications. Security risks such as unauthorized access, spoofing, or eavesdropping can be increased when switching between networks with different security levels. Additionally, protocol mismatch, configuration inconsistency, or authentication failure can occur when switching between network technologies with different standards and specifications. Lastly, hardware requirements, software updates, or policy enforcement can increase the cost and complexity of wireless network deployment when supporting multiple network technologies with different features.