An apparatus comprising: a reflector housing configured to be detachably coupled to an LED based illumination device configured to illuminate an environment, the reflector housing comprising: a flange having a surface facing the environment illuminated by the LED based illumination device; a reflector having an input port configured to receive a first amount of light emitted from the LED based illumination device and an output port through which light passes toward the environment, wherein the reflector is configured to redirect at least a portion of the first amount of light emitted from the LED based illumination device toward the output port; a sensor; a reflector interface module coupled to the reflector housing, the reflector interface module configured to receive at least one signal from the sensor; and a first communications interface subsystem (205, 207A, 208, 212, 220) configured to transmit and receive communications signals to and from the reflector housing, characterised in that: the sensor is coupled to the flange of the reflector housing such that at least a portion of the sensor faces the environment illuminated by the LED based illumination device wherein the sensor is communicatively coupled to the first communications interface subsystem; and wherein the first communications interface subsystem is configured to route the at least one signal from the sensor to the LED based illumination device when the reflector housing is detachably coupled to the LED based illumination device. a reflector housing configured to be detachably coupled to an LED based illumination device configured to illuminate an environment, the reflector housing comprising: a flange having a surface facing the environment illuminated by the LED based illumination device; a reflector having an input port configured to receive a first amount of light emitted from the LED based illumination device and an output port through which light passes toward the environment, wherein the reflector is configured to redirect at least a portion of the first amount of light emitted from the LED based illumination device toward the output port; a flange having a surface facing the environment illuminated by the LED based illumination device; a reflector having an input port configured to receive a first amount of light emitted from the LED based illumination device and an output port through which light passes toward the environment, wherein the reflector is configured to redirect at least a portion of the first amount of light emitted from the LED based illumination device toward the output port; a sensor; a reflector interface module coupled to the reflector housing, the reflector interface module configured to receive at least one signal from the sensor; and a first communications interface subsystem (205, 207A, 208, 212, 220) configured to transmit and receive communications signals to and from the reflector housing, characterised in that: the sensor is coupled to the flange of the reflector housing such that at least a portion of the sensor faces the environment illuminated by the LED based illumination device wherein the sensor is communicatively coupled to the first communications interface subsystem; and wherein the first communications interface subsystem is configured to route the at least one signal from the sensor to the LED based illumination device when the reflector housing is detachably coupled to the LED based illumination device. the sensor is coupled to the flange of the reflector housing such that at least a portion of the sensor faces the environment illuminated by the LED based illumination device wherein the sensor is communicatively coupled to the first communications interface subsystem; and wherein the first communications interface subsystem is configured to route the at least one signal from the sensor to the LED based illumination device when the reflector housing is detachably coupled to the LED based illumination device.