A data communication system comprising: at least one mobile apparatus of a user storing mobile directory information including information unique to the user and at least part of information of information processors in the user's home and at a location away from home and a personal directory, PDR, which stores original of various mobile directory information held by a plurality of users and which receives a service request from the mobile apparatus through a network and provides a directory service to the mobile apparatus according to the service request, further comprising: a service provider, wherein the service provider distributes content or provides a communication service on request of a mobile apparatus based on information obtained from the personal directory, further comprising: a space directory server which stores information of information processors in a local area and transmits the information of the nearby apparatuses to a requesting mobile apparatus, wherein the service provider receives a service request including information of nearby apparatuses included in the mobile directory information from the mobile apparatus and provides a service through the nearby apparatuses. at least one mobile apparatus of a user storing mobile directory information including information unique to the user and at least part of information of information processors in the user's home and at a location away from home and a personal directory, PDR, which stores original of various mobile directory information held by a plurality of users and which receives a service request from the mobile apparatus through a network and provides a directory service to the mobile apparatus according to the service request, further comprising: a service provider, wherein the service provider distributes content or provides a communication service on request of a mobile apparatus based on information obtained from the personal directory, further comprising: a space directory server which stores information of information processors in a local area and transmits the information of the nearby apparatuses to a requesting mobile apparatus, wherein the service provider receives a service request including information of nearby apparatuses included in the mobile directory information from the mobile apparatus and provides a service through the nearby apparatuses. a service provider, wherein the service provider distributes content or provides a communication service on request of a mobile apparatus based on information obtained from the personal directory, further comprising: a space directory server which stores information of information processors in a local area and transmits the information of the nearby apparatuses to a requesting mobile apparatus, wherein the service provider receives a service request including information of nearby apparatuses included in the mobile directory information from the mobile apparatus and provides a service through the nearby apparatuses. a space directory server which stores information of information processors in a local area and transmits the information of the nearby apparatuses to a requesting mobile apparatus, wherein the service provider receives a service request including information of nearby apparatuses included in the mobile directory information from the mobile apparatus and provides a service through the nearby apparatuses.