) With the advent of mobile health (mHealth), exciting opportunities now exist with remote monitoring systems capable of providing ubiquitous vigilance and new contextual insights into patient behavior and disease. Real- world observations can particularly be useful with pediatric populations in order to better understand the everyday situations and environments that contribute to myriad health issues. But there remains a critical, unmet need for a flexible, extensive platform that can enable secure data collection and transmission over a growing heteroge- neity of wearable and local environmental sensors. Standard methods to link sensors, mobile devices, and data centers are needed to ensure extensibility and future broad adoption of mHealth platforms. Project 1 supports the communication of sensors with mobile devices in an integrative, modular manner. This part of the Los Angeles PRISMS Center focuses on the design and development of application programming interfaces (APIs) and a standardized software platform that addresses the capture of data from sensors, exe- cutes local processing as needed, and securely transfers data and receives instructions to/from a data center (i.e., the PRISMS U24 data and software coordination and integration center). The innovations and develop- ments behind Project 1 are an important piece of the Biomedical REAl-Time Health Evaluation for Pediatric Asthma (BREATHE) platform. A key objective of Project 1 is the specification of a standard protocol for sensor descriptions, configuration, and data collection. Two communication APIs will be developed through Project 1: between the sensors and smartphone; and between the smartphone and data center. The APIs will enable: 1) querying of available sensors and/or smartphones; 2) scheduling and configuration of data collection on the smartphone (e.g., what sensors to connect to) and sensors (e.g., sampling frequency); and 3) automatically uploading time- and location-stamped data to the data center. Interwoven throughout the design and implemen- tation of the APIs are security and privacy mechanisms, applied across the multiple points of communication involved in gathering and handling sensor data. Recognizing the import of low-power design of sensors and mobile devices on user acceptance and compliance with mHealth applications, Project 1 also develops novel algorithms to optimize sensor usage and information gain, while minimizing power usage, thereby enabling sen- sors and devices to remain powered over the long-term and without interruption. Development of the mobile device platform and its user interfaces is done in coordination with Project 2; and field testing is considered with Project 3. The approaches taken in Project 1 provide a foundation upon which new U01 PRISMS sensors can be readily integrated.