Levi The root of the name Levi is "lavah" (accompany or become attached).    Leah knew that Yaakov was destined to beget the Twelve Tribes from his four wives.  Now that Leah had given birth to three sons, she had successfully completed her portion, 1/4 of the number of sons that Yaakov would have.  With this name, Leah prayed that HaShem would "accompany" her children and that that they would serve in the House of HaShem (Bereishit 29:34) (MeAm Lo'ez)
Encampment Position - All four directions around the Mishkan

The Mishkan was placed at the very center of the nation.  Its site was called Machaneh Shechinah (Camp of the Shechinah).  It was the innermost and holies camp.  It was surrounded on all four sides by the Leviim.  The area where they encamped was known as Machaneh Leviya (Camp of the Leviim).  This camp was less holy than that of the Shechinah camp.