McALLEN, Texas (Border Report) — U.S. Immigration and Customs Enforcement is increasing the use of ankle monitors, an older form of technology for migrants not in detention facilities while their immigration cases are under review, according to an analysis of new data by Border Report.

As of Saturday, the number of migrants on ankle monitors was 29,089 nationwide, according to the latest ICE data published on the agency’s website.

That’s up from 28,070 migrants on ankle monitors as of Aug. 23 in the agency’s Alternatives to Detention program, according to data from Transactional Records Access Clearinghouse (TRAC).

The ankle monitors use satellite GPS technology, according to ICE.

The number of migrants monitored via the SmartLINK app decreased from 150,784 as of Aug. 23, to 148,717 as of Sept. 6, a comparison of the data found.

For the past few years, the number of migrants given devices with the SmartLINK app to monitor their whereabouts had been increasing. The app allows migrants to send photos of themselves and check in with ICE officials and to access calendars with their upcoming court date information. It is not a cellphone, however, and does not allow them to make calls or scroll the Internet.

The number of migrants placed on ankle monitors in El Paso is more than double the number on SmartLINK apps. The number supervised through ankle monitors in Harlingen, Texas, is about half the number now on SmartLINK apps.

The number of migrants monitored via a newer wristworn GPS device also decreased to 2,547 from 2,623 during that time period, Border Report has found.

The wristworn devices use satellite GPS but also have software enabling facial matching, direct messaging, and push notifications, ICE says.

The total number of migrants placed in the Alternatives to Detention program was 181,401 as of Sept. 6, ICE reports.

“ICE’s Alternatives to Detention (ATD) program exists to ensure compliance with release conditions and provides important case management services,” the agency says on its website. The “program utilizes case management and technology tools to support aliens’ compliance with release conditions while on ICE’s non-detained docket.”

The daily tech monitoring costs for the various programs was $234,153.82 as of Sept. 6, according to ICE.

The daily cost per ATD Intensive Supervision Appearance Program (ISAP) participant is less than $4.20 per day — much less than the $152 per day fee for migrants held in detention facilities, the agency says.

The total number of migrants held in detention facilities nationwide was 58,766 as of Sept. 7.

Sandra Sanchez can be reached at SSanchez@BorderReport.com.