Alexander Gellman

Sonitrol Corp. engages in manufacturing and marketing of electronic security products for commercial, industrial and institutional clients in North America. It offers audio intrusion detection systems; access control systems; video surveillance solutions; and fire detection products, including smoke and heat detection, water flow and sprinkler monitoring, temperature monitoring, elevator recall, voice evacuation system, and duct detection solutions. The company was founded by Robert W. Baxter on June 16, 1960 and is headquartered in Berwyn, PA.

Global Tower LLC owns, manages and master leases antenna sites on towers and commercial real estate rooftops. The company was founded on September 8, 2003 and is headquartered in Boston, MA.

Apex Site Management, Inc., was a full service real estate management and consulting company specializing in negotiating telecommunication access and transmitting agreements between property owners and telecommunications companies. The firm was located in Conshohocken, PA.

Part of SpectraSite Communications, Inc., SpectraSite Transco Communications SAS provides wireless infrastructure solutions. The company is based in Paris, France.

Horizon Cellular Telephone Co. LP owns and operates cellular telephone systems. The private company is based in Malvern, PA and has subsidiaries in the United States. The company was founded by Alexander L. Gellman.

Vertical Bridge Holdings, LLC operates as a wireless communication infrastructure leasing company. It owns, operates and manages telecommunications towers, rooftops and site locations. The company was founded by Alexander L. Gellman, Bernard A. Borghei and Michael J. Belski in 2014 and is headquartered in Boca Raton, FL.

CIG Wireless Corp. develops, operates and owns wireless and broadcast communication towers in the United States. Its business consists of leasing antenna space on multi-tenant communication sites to wireless service providers. The company was founded on 12 February, 2008 and is headquartered in Wellington, FL.

The Wireless Infrastructure Association represents companies involved in the development, building, ownership, and operation of wireless infrastructure in the United States. The non-profit company is based in Alexandria, VA. Patrick Halley has been the CEO of the company since 2022. Its members include wireless carriers, infrastructure providers, and professional services firms that collectively own and operate over 135,000 telecommunications facilities worldwide.