HA 

Home Agent

HDLC 

High-level Data Link Control

HDML 

Handheld Device Markup Langage (Unwired Planet)

HDSF 

High Density Fixed Service

HDSL 

High bit rate Digital Subscriber Line

HEC 

Header Error Control

HF 

Human Factors

HFC 

Hybrid Fibre Coax

HILN 

Harmonic Individual Line and Noise

HLR 

Home Location Register

HNO 

Host Network Operator

HO 

Handover

HOLD 

Call hold

HPLMN 

Home Public Land Mobile Network

HSCSD 

High Speed Circuit Switched Data

HSDPA 

High speed downlink  Packet Access

HSS 

Home Subscriber Server

HTML 

Hypertext Markup Language

HTTP 

Hypertext Transfer Protocol

HTTP-S 

Secure Hypertext Transfer Protocol

HVXC 

Harmonic Vector Exitation Coding