The technology chosen for this relies on a wireless distributed sensor-network (WDSN). As part of this EU FP7 project, Haifa is one of the case studies, where a WDSN for measuring ambient gaseous pollutants (NO2, NO, O3, CO) will be (and is partially already) deployed. In the last year, we focused on formulating a novel field calibration protocol for the sensors, and on extending the number of distributed units and the study area. Air pollutant concentrations from the extended network deployment (phase II) was collected by 17 functional metal-oxide-based sensor units. The collected data during Apr-Aug 2014 (Year 4 of TCEEH) were exploited for deriving a general protocol for field chain calibration and evaluation of measurement uncertainties. A manuscript discussing the protocol, its performance and prospects for its improvements is under preparation. Phase III of the deployment was launched in late spring, 2015. In this phase we use a new type of sensor units, based on electrochemical sensors. To date, 21 such units are already deployed and measure urban air quality in different sites. Data collected by these units will be used for further evaluation of the said calibration process and are expected to provide a basis for spatial characterization of pollutants in the study area. This will be done at two sub-stages: with the pods collocated with a reference monitoring station and with pods that are deployed in three adjacent neighborhoods in Haifa: Neve-Shaanan, Ramat Chen, and Ramat Sapir.