title: Cartographic Analysis of Antennas and Towers: A Novel Approach to Improving the Implementation and Data Transmission of mHealth Tools on Mobile Networks.
abstract: BACKGROUND
  Most mHealth tools such as short message service (SMS), mobile apps, wireless pill counters, and ingestible wireless monitors use mobile antennas to communicate. Limited signal availability, often due to poor antenna infrastructure, negatively impacts the implementation of mHealth tools and remote data collection. Assessing the antenna infrastructure prior to starting a study can help mitigate this problem. Currently, there are no studies that detail whether and how the antenna infrastructure of a study site or area is assessed.
  
  
  OBJECTIVE
  To address this literature gap, we analyze and discuss the use of a cartographic analysis of antennas and towers (CAAT) for mobile communications for geographically assessing mobile antenna and tower infrastructure and identifying signal availability for mobile devices prior to the implementation of an SMS-based mHealth pilot study.
  
  
  METHODS
  An alpha test of the SMS system was performed using 11 site staff. A CAAT for the study area's mobile network was performed after the alpha test and pre-implementation of the pilot study. The pilot study used a convenience sample of 11 high-risk men who have sex with men who were given human immunodeficiency virus test kits for testing nonmonogamous sexual partners before intercourse. Product use and sexual behavior were tracked through SMS. Message frequency analyses were performed on the SMS text messages, and SMS sent/received frequencies of 11 staff and 11 pilot study participants were compared.
  
  
  RESULTS
  The CAAT helped us to successfully identify strengths and weaknesses in mobile service capacity within a 3-mile radius from the epicenters of four New York City boroughs. During the alpha test, before CAAT, 1176/1202 (97.84%) text messages were sent to staff, of which 26/1176 (2.21%) failed. After the CAAT, 2934 messages were sent to pilot study participants and none failed.
  
  
  CONCLUSIONS
  The CAAT effectively illustrated the research area's mobile infrastructure and signal availability, which allowed us to improve study setup and sent message success rates. The SMS messages were sent and received with a lower fail rate than those reported in previous studies.
authors.affiliation: HIV Center for Clinical and Behavioral Studies, New York State Psychiatric Institute, Columbia University, New York, NY, United States. wb2253@columbia.edu.
authors.forename: William
authors.identifier: http://orcid.org/0000-0003-4322-4859
authors.initials: W
authors.lastname: Brown Iii
authors.forename: Mobolaji
authors.identifier: http://orcid.org/0000-0003-4820-0805
authors.initials: M
authors.lastname: Ibitoye
authors.forename: Suzanne
authors.identifier: http://orcid.org/0000-0001-6202-6001
authors.initials: S
authors.lastname: Bakken
authors.forename: Rebecca
authors.identifier: http://orcid.org/0000-0003-2184-4045
authors.initials: R
authors.lastname: Schnall
authors.forename: Iván
authors.identifier: http://orcid.org/0000-0001-6421-329X
authors.initials: I
authors.lastname: Balán
authors.forename: Timothy
authors.identifier: http://orcid.org/0000-0002-0859-0071
authors.initials: T
authors.lastname: Frasca
authors.forename: Alex
authors.identifier: http://orcid.org/0000-0001-5888-031X
authors.initials: A
authors.lastname: Carballo-Diéguez
keywords: HIV; SMS; antenna; cartographic analysis; mHealth; mobile health; short message service; text messaging; wireless