This　paper　presents　an　integrated　boundary　protection　scheme　for　power　transmission　line　systems.　The　scheme　combines　the　latest　developments　in　two　areas　of　power　system　protection,　the　transient　based　protection　and　the　integrated　protection.　In　the　proposed　scheme,　an　integrated　relay　based　on　boundary　protection　principle　installed　at　a　substation　is　responsible　for　the　protection　of　all　transmission　lines　associated　with　the　substation.　The　relay　is　able　to　offer　fast　trip　for　any　fault　on　its　protected　line　sections　without　the　need　for　communication　link.　The　paper　outlines　the　integrated　protection　system　based　on　substation　communication　network,　gives　a　description　to　the　basic　principle　and　algorithm　of　the　boundary　protection　technique.　Some　typical　simulation　results　are　then　used　to　demonstrate　the　performance　of　the　scheme.　©　2007　RPS.