Learning Center
Connectivity resilience
Connectivity resilience is a system's ability to keep working when a link, a provider or the cloud fails. Learn how Wi-Fi Direct, Wi-Fi Aware and satellite messaging work, why networks fail in crowds and outages, and how failover and graceful degradation are designed.
Direct links
How does Wi-Fi Direct work?Discovery, choosing a group owner, and sockets, with no access point in between.→How does Wi-Fi Aware work?Clusters, publish and subscribe, then a direct data path with no access point.→What is Apple Multipeer Connectivity?Apple's framework for linking nearby Apple devices, deprecated in Xcode 27.→How does direct-to-phone satellite messaging work?Phone to satellite to ground gateway, and why it needs open sky and patience.→Can an iPhone and an Android phone connect directly without internet?Which radios an iPhone and an Android phone share, and which stay on one platform.→Multipeer Connectivity alternatives that work with AndroidNearby Connections, Wi-Fi Direct, Wi-Fi Aware and Bluetooth LE compared with Multipeer.→
Outages and failure
Why do network outages happen?Bad changes, latent bugs, overload, hidden dependencies and cut cables.→What is a single point of failure?The one part that takes everything down with it, and how to find it.→What is failover?Switching to a standby system or path when the active one fails.→What is multipath networking?One connection, several paths, so losing a link does not end the session.→What is a cellular dead zone?Places a phone cannot reach a usable mobile network, and what still works there.→Why does mobile data fail in crowds?Full bars, no data: how a crowd shares one cell's capacity and access channel.→What is network congestion?When traffic exceeds what a link can carry, queues fill and senders must back off.→What is a captive portal?Wi-Fi that looks connected but blocks the internet until someone signs in.→What happens to apps when the cloud goes down?What breaks when a provider fails, what real outages show, and how apps cope.→What is graceful degradation?Keep the core working, with less, when part of the system fails.→What is disaster-resilient communication?How carriers, regulators, responders and apps keep information moving in a disaster.→