A personal security equipment unit for securing a person (P1, P2, P3), the security equipment unit comprising: - a wristband that is suitable to be wrapped around a wrist of a person (P1, P2, P3). - a box casing held by the wristband, the whole assembly of the box casing and the wristband being wearable by the person (P1, P2, P3), the box casing including: - a receiver capable of receiving data originating from a global communication network and from a local communication network, the local communication network grouping together the security equipment unit and at least one other security equipment unit, - a processor capable of associating with each data item a given degree of dangerousness for the person (P1, P2, P3), the processor being capable of sending data to be communicated to the person (P1, P2, P3) wearing said security equipment unit and being capable of transmitting data to be transmitted, - an interface capable of communicating to the person (P1, P2, P3) data sent by the processor, - a transmitter capable of transmitting data transmitted by the processor, the transmitter being capable of transmitting data over the global communication network and the local communication network, and - an accessibility detector for detecting accessibility to the network, the detector being capable of detecting access to the global communication network, the receiver receiving data coming from the local communication network and the transmitter transmitting data over the local communication network when the detector detects that the global communication network is not accessible for the security equipment unit, the security equipment unit being capable of operating in accordance with at least two modes of operation, in particular three modes of operation (M1, M2, M3), with each mode of operation (M1, M2, M3) being associated in a one-to-one manner with a threshold degree of dangerousness (DDS1, DDS2, DDS3), the data that the processor is capable to send in one mode of operation (M1, M2, M3) being the data associated with a degree of dangerousness that is greater than or equal to the threshold degree of dangerousness (DDS1, DDS2, DDS3) of the mode of operation (M1, M2, M3) considered. - a wristband that is suitable to be wrapped around a wrist of a person (P1, P2, P3). - a box casing held by the wristband, the whole assembly of the box casing and the wristband being wearable by the person (P1, P2, P3), - a receiver capable of receiving data originating from a global communication network and from a local communication network, the local communication network grouping together the security equipment unit and at least one other security equipment unit, - a processor capable of associating with each data item a given degree of dangerousness for the person (P1, P2, P3), the processor being capable of sending data to be communicated to the person (P1, P2, P3) wearing said security equipment unit and being capable of transmitting data to be transmitted, - an interface capable of communicating to the person (P1, P2, P3) data sent by the processor, - a transmitter capable of transmitting data transmitted by the processor, the transmitter being capable of transmitting data over the global communication network and the local communication network, and - an accessibility detector for detecting accessibility to the network, the detector being capable of detecting access to the global communication network, the receiver receiving data coming from the local communication network and the transmitter transmitting data over the local communication network when the detector detects that the global communication network is not accessible for the security equipment unit,