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Wi-Fi Roaming refers to the ability of a wireless device to seamlessly move from one access point to another without dropping the connection or experiencing significant latency. In enterprise environments, where mobility is key, this ensures that employees remain connected, whether they're moving from one conference room to another or navigating large facilities.
Let’s dive a little deeper. Here’s what we cover below:
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What Is Wi-Fi Roaming?
Wi-Fi roaming refers to the ability of a Wi-Fi-enabled device to stay connected to a network as it moves from one location to another. The goal is to switch seamlessly between different access points (APs) without losing connectivity.
In Wi-Fi networks — and especially in enterprise environments — multiple APs are often deployed to cover larger areas, like airports, shopping malls, office buildings, warehouses, campuses, etc. As users move within those areas, their devices need to be able to switch between APs to ensure continuous and stable connections.
How Does Wi-Fi Roaming Work?
Wi-Fi roaming was developed to provide end users with consistent, reliable Wi-Fi connections across multiple APs. This is accomplished using a variety of standards and protocols, such as the IEEE 802.11r (Fast Basic Service Set Transition) standard, that define how devices communicate with APs and how the handover process takes place.
Here is an overview of how Wi-Fi roaming works:
- Step 1: Scanning for Access Points
- Step 2: Checking for Neighbor Reports
- Step 3: Deciding to Roam
- Step 4: Authentication and Fast Transition
- Step 5: Transition and Handover
- Step 6: Security Handover
- Step 7: Seamless Connectivity
Let’s cover these one at a time…
- Scanning for Access Points: As a device moves within a Wi-Fi network's coverage area, it periodically scans for nearby APs. The scanning process involves checking the signal strength and other relevant parameters of available APs.
- Checking for Neighbor Reports: Likewise, APs periodically broadcast information about neighboring APs. These ‘Neighbor Reports’ include information such as signal strength, channel information, and supported capabilities. Devices use this information to make informed decisions about potential targets for roaming.
- Deciding to Roam: Once a device evaluates neighboring APs, it can decide to roam to one of them using factors such as signal strength, load on the current AP, and other quality metrics.
- Authentication and Fast Transition: Once the device decides to roam, it initiates the authentication process with the target AP. The IEEE 802.11r standard plays a crucial role in enabling fast and secure roaming. It allows devices to pre-authenticate with the target APs, reducing the time it takes to complete the handover.
- Transition and Handover: This is the moment when the device transitions its connection from the current access point to the target access point. During this transition, the connection state is transferred and the device continues communication seamlessly.
- Security Handover: The security credentials established with the original AP need to be smoothly transferred to the new AP. This ensures that the device remains securely connected to the network throughout the roaming process.
- Seamless Connectivity: Once the handover is complete, the device is now connected to the new AP, and communication resumes without the user experiencing any noticeable interruption.
Benefits of Wi-Fi Roaming
Wi-Fi roaming is essential for creating robust, user-friendly wireless networking environments. It ensures that users can move freely within a coverage area while maintaining a stable and high-quality connection, leading to an overall positive experience with wireless connectivity.
Broadly speaking, Wi-Fi roaming comes with five primary benefits:
- Continuous Connectivity, Seamless Handover
- Optimized Performance, Efficient Use of Network Resources, and Load Balancing
- Support for Mobility and Large Environments
- Enhanced Battery Life
- Improved User Experiences
Let’s dig into the details…
- Continuous Connectivity, Seamless Handover: The seamless handover process minimizes the impact on ongoing applications and services. Users can stay connected to the Wi-Fi network without experiencing drops in connectivity or interruptions in data transmission as they move between different areas covered by different access points.
- Optimized Performance, Efficient Use of Network Resources, and Load Balancing: Roaming helps distribute device connections more evenly across multiple APs, preventing congestion on a single AP. This optimization leads to improved network performance and better utilization of available resources, while reducing the likelihood that certain APs become overloaded as others remain underutilized.
- Support for Mobility and Large Environments: Wi-Fi roaming is crucial in environments where users are mobile, such as airports, train stations, shopping centers, and large office buildings. It allows users to maintain connectivity as they move from one location to another.
- Enhanced Battery Life: Efficient roaming contributes to improved power management, as devices can connect to the AP with the best signal quality. This can result in better battery life for mobile devices.
- Improved User Experiences: Wi-Fi roaming enhances the overall user experience by ensuring that applications, such as voice calls, video streaming, and online gaming, maintain a stable connection without noticeable delays or quality degradation during roaming.
How Enterprises Can Benefit from Wi-Fi Roaming
It suffices to say that the benefits of Wi-Fi roaming don’t stop at the boundaries of enterprise environments. Indeed, roaming plays a crucial role in pretty much every modern organization.
Here are some specific advantages for enterprises:
- Improved Productivity
- Optimized Network Performance
- Support for BYOD Environments
- Increased Security
- Guest Access Management
- Scalability
- Cost Savings
Once again, let’s quickly touch on these individually…
- Improved Productivity: Employees can move freely within the office environment without experiencing disruptions in their Wi-Fi connectivity. This is crucial for tasks that involve real-time communication, collaboration, and access to cloud-based applications, ultimately contributing to increased productivity.
- Optimized Network Performance: Wi-Fi roaming helps distribute device connections across multiple access points, preventing network congestion and optimizing performance. This is especially important in large office spaces where a single access point might not efficiently serve all connected devices.
- Support for BYOD (Bring Your Own Device) Environments: Many enterprises allow employees to use their own devices for work purposes. Wi-Fi roaming supports a BYOD environment by ensuring that devices can seamlessly switch between access points, providing a consistent user experience.
- Increased Security: Security protocols, including the 802.11r standard, contribute to a secure and efficient handover process during Wi-Fi roaming. This ensures that sensitive data remains protected as devices move between access points.
- Guest Access Management: In enterprises where guest access is provided, Wi-Fi roaming facilitates a smooth transition for guest devices as they move within the premises. This improves the experience for visitors and maintains a secure separation between guest and corporate networks.
- Scalability: As enterprises grow and evolve, Wi-Fi roaming supports the scalability of the network. Additional APs can be deployed to accommodate the increasing number of connected devices and ensure consistent coverage throughout the expanding workspace.
- Cost Savings: By optimizing network performance and reducing the likelihood of network disruptions, Wi-Fi roaming can contribute to cost savings by minimizing downtime and support-related issues.
How to Optimize Wi-Fi Roaming on Your Network
Alright, so now that we’ve covered the basics of Wi-Fi roaming, including how it benefits enterprises, let’s turn our attention to how it can be optimized such that businesses can reach their full roaming potential. To begin, let’s look at the key elements of Wi-Fi Roaming. Understanding these will enable us to identify the various avenues for enhancing and streamlining performance.
Key Aspects of Wi-Fi Roaming
Signal Strength and Quality
Unsurprisingly, a Wi-Fi AP’s signal strength and quality are critical when it comes to determining whether a device should roam to another access point. Devices often use signal strength metrics to decide when to initiate the handover process. By updating your environment with modern, high-performing APs, you can shrink and eliminate gaps in your coverage.
Client Capabilities
Likewise, the capabilities of various Wi-Fi clients (laptops, smartphones, tablets, wearables, and other devices) play a role in how effectively they can roam. Older devices or those with less sophisticated roaming capabilities may not transition as smoothly as newer devices that support advanced roaming features. It’s especially important to monitor how various client driver / adapter combinations perform on your network to inform future upgrades and device acquisitions.
Access Point Density and Placement (Network Topology)
Wi-Fi roaming is also impacted by the density and placement of APs in a network coverage area. By properly spacing APs, you can ensure that there are enough options for devices to roam without losing connectivity. Moreover, understanding common causes of interference — such as metal objects, concrete walls, tinted windows, and, of course, other Wi-Fi enabled devices — enables you to optimize AP placement further by reducing the number of potential obstructions.
Network Load and Capacity
The overall load on the Wi-Fi network and the capacity of individual APs impact the effectiveness of roaming. Load balancing mechanisms help distribute connected devices across access points, preventing congestion. So, it’s important to monitor which APs are carrying the most weight and which are carrying the least. These insights can inform future improvements, such as how to place existing APs, where to add new APs, and where APs may not be entirely necessary.
Administrative Settings and Policies
As a network administrator, you can configure settings and policies that influence roaming behavior. These may include roaming thresholds, which determine when a device should initiate roaming based on signal strength or other criteria.
Quality of Service (QoS) Settings
QoS settings on the network can influence how different types of traffic are prioritized during roaming. This ensures that critical applications, such as voice or video communication, receive the necessary priority for a seamless user experience.
Roaming Decision Algorithms
Roaming decision algorithms on devices and access points influence when and how devices initiate the roaming process. These algorithms consider factors such as signal strength, load balancing, and the quality of the connection.
Fast Transition (802.11r)
The implementation of the Fast Basic Service Set Transition (802.11r) standard is crucial for reducing the time it takes for devices to transition between access points. It enables pre-authentication, making the roaming process faster and more efficient.
Security Protocols
Security protocols, including those defined in the IEEE 802.11 standard, ensure a secure handover of the connection during Wi-Fi roaming. This includes transferring security credentials from one access point to another without compromising data integrity.
Neighbor Report Information
Access points periodically broadcast information about neighboring access points in the form of a Neighbor Report. This information is crucial for devices to make informed decisions about potential target access points for roaming.
Common Issues with Wi-Fi Roaming
While Wi-Fi roaming is designed to provide seamless connectivity as devices move within a network, there are several common issues that can arise. These issues can impact the user experience and overall network performance.
Common problems associated with Wi-Fi roaming include:
- Roaming Latency
- Sticky Clients
- Unpredictable Roaming Decisions
- Interference and Signal Quality
- Incomplete Security Handover
- Inefficient Load Balancing
- Network Congestion
- Device Compatibility
- Lack of Fast Transition Support
- Configuration Issues
- Roaming Between Different SSIDs
Let’s quickly touch on each…
- Roaming Latency: Roaming latency refers to the delay or interruption in connectivity that users may experience during the handover process between access points. If roaming is not optimized, it can result in noticeable delays, affecting real-time applications such as voice calls or video streaming.
- Sticky Clients: Some devices may exhibit "sticky client" behavior, where they are reluctant to disconnect from their current access point even when a better one is available. This can lead to suboptimal connectivity and uneven distribution of client devices across access points.
- Unpredictable Roaming Decisions: Roaming decisions are made by the devices, and sometimes they may not make optimal choices. Factors such as signal strength alone may not be sufficient, leading to devices sticking to a weaker connection or frequently initiating unnecessary handovers.
- Interference and Signal Quality: As noted above, interference from other Wi-Fi networks or electronic devices can impact signal quality, affecting the ability of devices to roam smoothly. In environments with high interference, devices may struggle to maintain a stable connection during roaming.
- Incomplete Security Handover: During the roaming process, security credentials need to be transferred from the current access point to the new one. In some cases, incomplete security handovers can result in authentication issues, leading to connectivity problems or disconnections.
- Inefficient Load Balancing: In scenarios where load balancing mechanisms are not optimized, some access points may become overloaded while others remain underutilized. This can result in degraded performance for devices connected to congested access points.
- Network Congestion: Roaming can contribute to network congestion if not managed properly. A sudden influx of roaming devices can strain the network, affecting the performance of all connected devices.
- Device Compatibility: Older devices or devices from different manufacturers may have varying levels of support for roaming standards. This can lead to inconsistent roaming behavior across different types of devices in the network.
- Lack of Fast Transition Support: If the network infrastructure and devices do not support standards like IEEE 802.11r (Fast BSS Transition), the roaming process may take longer, resulting in increased latency and potential disruptions.
- Configuration Issues: Incorrect configurations, such as suboptimal roaming threshold settings or misconfigured security parameters, can lead to issues with Wi-Fi roaming. Regular network audits and optimizations are important to address these issues.
- Roaming Between Different SSIDs: Roaming between access points with different Service Set Identifiers (SSIDs) or network segments can result in temporary disconnections and may not provide a seamless experience for users.
To address these issues, network administrators should perform thorough testing, implement best practices for Wi-Fi roaming, and stay informed about firmware updates and improvements in roaming standards. Regular monitoring and optimization of the network configuration can help mitigate many of the common challenges associated with Wi-Fi roaming.
How to Measure, Monitor, and Optimize Wi-Fi Roaming
This takes us to the 7SIGNAL Wi-Fi monitoring platform. With its unique combination of hardware and software elements, you’ll be able to monitor roaming issues from the outside in.
The 7SIGNAL platform leverages Wi-Fi sensors to gain visibility into WLAN performance. These sensors enable you to measure traffic to various APs and identify areas in your network where performance is lagging and the potential causes.
In addition, the 7SIGNAL platform leverages a SaaS application which is installed on end-user devices (Windows, Android, MacOS, Linux, GoogleTV, iGEL) and used to monitor digital experiences from the client perspective. This means you’ll have insight into how various manufacturers, software versions, adapters, drivers, and other specifications perform on your network.
Finally, 7SIGNAL’s performance monitoring dashboards enable you to observe and visualize everything in one place. This will help you catch issues in real time, prioritize how you address them, and reduce MTTR (mean time to resolve).
By providing a comprehensive health overview and allowing deep dives into specific issues, 7SIGNAL ensures that network engineers and IT teams are always a step ahead in ensuring optimal Wi-Fi performance. By complementing WLAN vendors and offering a distinctive outside-in perspective, 7SIGNAL is setting new standards in Wi-Fi network performance and user experience optimization.
Learn More From the 7SIGNAL Experts
We’re always here to answer your Wi-Fi questions at 7SIGNAL. Our enterprise Wi-Fi optimization platform helps you plan and execute a healthier network. Contact us to learn more.
7SIGNAL® is the leader in enterprise Wi-Fi optimization, providing insight into wireless networks and control over Wi-Fi performance so businesses and organizations can thrive. Our cloud-based platform continually tests and measures Wi-Fi performance at the edges of the network, enabling fast solutions to digital experience issues and stronger connections for mission-critical users, devices, and applications. Learn more at www.7signal.com.