This study examines the structure and tie strengths in mobile communication networks using data from millions of mobile phone calls. The research reveals that the strength of ties between individuals is closely related to the local structure of the network. This coupling has significant implications for the network's stability and information diffusion. The study finds that social networks are robust to the removal of strong ties but fall apart after a phase transition if weak ties are removed. This suggests that weak ties play a crucial role in maintaining the network's connectivity. The study uses mobile phone call records to construct a map of a society-wide communication network, capturing the interaction patterns of millions of individuals. The data allows for the exploration of the relationship between network topology and tie strengths, which was previously inaccessible at the societal level. The results show that the network has a skewed degree distribution with a fat tail, indicating that most users have few connections, but a small minority have many. The tie strength distribution is also broad, with a small fraction of users spending hours chatting with each other. The study also finds that the strength of a tie between two individuals is influenced by the nature of their relationship and the local network structure. This is in contrast with the dyadic hypothesis, which suggests that tie strength depends only on the relationship between two individuals. The study supports the strength of weak ties hypothesis, which states that the strength of a tie between A and B increases with the overlap of their friendship circles, resulting in the importance of weak ties in connecting communities. The study also examines the stability of the network to the removal of either strong or weak ties. It finds that removing weak ties leads to a sudden, phase transition-driven collapse of the network, while removing strong ties results in a gradual shrinkage. This finding is counterintuitive, as strong ties are typically believed to play a more important structural role than weak ties. The study also investigates the dynamics of information diffusion on the network. It finds that information spreads more quickly on networks where all tie strengths are equal, but this is due to dynamic trapping of information in communities. The study shows that the distribution of tie strengths through which individuals first learn about news has a prominent peak at intermediate strengths, indicating that most individuals learn about news through ties of intermediate strength. The study concludes that weak ties are crucial for maintaining the network's structural integrity, while strong ties play an important role in maintaining local communities. However, both weak and strong ties are ineffective for information transfer, as most news reaches individuals through ties of intermediate strength. The study highlights the importance of considering tie strengths and local network structure when modeling processes in social networks.This study examines the structure and tie strengths in mobile communication networks using data from millions of mobile phone calls. The research reveals that the strength of ties between individuals is closely related to the local structure of the network. This coupling has significant implications for the network's stability and information diffusion. The study finds that social networks are robust to the removal of strong ties but fall apart after a phase transition if weak ties are removed. This suggests that weak ties play a crucial role in maintaining the network's connectivity. The study uses mobile phone call records to construct a map of a society-wide communication network, capturing the interaction patterns of millions of individuals. The data allows for the exploration of the relationship between network topology and tie strengths, which was previously inaccessible at the societal level. The results show that the network has a skewed degree distribution with a fat tail, indicating that most users have few connections, but a small minority have many. The tie strength distribution is also broad, with a small fraction of users spending hours chatting with each other. The study also finds that the strength of a tie between two individuals is influenced by the nature of their relationship and the local network structure. This is in contrast with the dyadic hypothesis, which suggests that tie strength depends only on the relationship between two individuals. The study supports the strength of weak ties hypothesis, which states that the strength of a tie between A and B increases with the overlap of their friendship circles, resulting in the importance of weak ties in connecting communities. The study also examines the stability of the network to the removal of either strong or weak ties. It finds that removing weak ties leads to a sudden, phase transition-driven collapse of the network, while removing strong ties results in a gradual shrinkage. This finding is counterintuitive, as strong ties are typically believed to play a more important structural role than weak ties. The study also investigates the dynamics of information diffusion on the network. It finds that information spreads more quickly on networks where all tie strengths are equal, but this is due to dynamic trapping of information in communities. The study shows that the distribution of tie strengths through which individuals first learn about news has a prominent peak at intermediate strengths, indicating that most individuals learn about news through ties of intermediate strength. The study concludes that weak ties are crucial for maintaining the network's structural integrity, while strong ties play an important role in maintaining local communities. However, both weak and strong ties are ineffective for information transfer, as most news reaches individuals through ties of intermediate strength. The study highlights the importance of considering tie strengths and local network structure when modeling processes in social networks.