ITU‐T's Technical Reports and Specifications 239 Figure 24 – Convergence at the optical layer MPLS (Multiprotocol Label Switching) Using MPLS the traffic engineering capabilities are integrated into Layer 3 (OSI) which optimizes the routing of IP traffic through the guidelines established by the topology and the trunk capacities. MPLS IP VPN gives a network of separate and independent communication for all its offices in the Telecommunications Network. Its benefits are: Access to all information wirelessly. Connecting stable, private and secure. Availability for teleconferencing, video‐calls and unlimited exchange of information in real time. Total availability of corporate headquarters from a single point. Implementation of loyalty systems and databases such as CRM, SAP, ORACLE, ERP, etc. Transmission of data, images and voice. MPLS could be divided into 2 category, MPLS for user access network, MPLS‐TP (Transport Profile) for transport network. 2.1.2.2 Access networks These are shaped by fixed and mobile access, preferably by broadband communication networks. Mobile networks are especially important for a smart sustainable city to permit permanent and wireless connection of objects, people and environments