Leases

Tenant Contracts

The following table is a summary of the rental cash payments owed to the Company, as a lessor, by tenants pursuant to contractual agreements in effect as of December 31, 2011. Generally, the Company's contracts with its tenants provide for (1) annual escalations and multiple renewal periods at the tenant's option and (2) only limited termination rights at the applicable tenant's option through the current term. As of December 31, 2011, the weighted-average remaining term of tenant contracts is approximately nine years, exclusive of renewals at the tenant's option. The tenants' rental payments included in the table below are through the current terms with a maximum current term of 20 years and do not assume exercise of tenant renewal options.



	Years Ending December 31,
	2012		2013		2014		2015		2016		Thereafter		Total
Tenant leases	$	1,661,458	$	1,666,996	$	1,631,813	$	1,575,337	$	1,468,813	$	9,185,611	$	17,190,028

Operating Leases

The following table is a summary of rental cash payments owed by the Company, as lessee, to landlords pursuant to contractual agreements in effect as of December 31, 2011. The Company is obligated under non-cancelable operating contracts for land interests under 71% of its towers, office space and equipment. In addition, the Company manages 600 towers owned by third parties. The majority of these operating lease agreements have certain termination rights that provide for cancellation after a notice period. The majority of the land interests and managed tower leases have multiple renewal options at the Company's option and annual escalations. Lease agreements may also contain provisions for a contingent payment based on revenues or the gross margin derived from the wireless infrastructure located on the leased land interest. Approximately 73% and 89% of the Company's site rental gross margins for the year ended December 31, 2011, are derived from towers where the land interest under the tower is owned or leased with final expiration dates of greater than 20 years and ten years, respectively, inclusive of renewals at the Company's option. The operating lease payments included in the table below include payments for certain renewal periods at the Company's option up to the estimated wireless infrastructure useful life of 20 years and an estimate of contingent payments based on revenues and gross margins derived from existing tenant leases.



	Years Ending December 31,
	2012		2013		2014		2015		2016		Thereafter		Total
Operating leases	$	301,264	$	305,278	$	307,267	$	308,801	$	311,242	$	3,907,901	$	5,441,753

Rental expense from operating leases was $338.3 million, $330.1 million and $316.2 million, respectively, for the years ended December 31, 2011, 2010 and 2009. The rental expense was inclusive of contingent payments based on revenues or gross margin derived from the wireless infrastructure located on the leased land interests of $56.4 million, $55.1 million and $53.1 million, respectively, for the years ended December 31, 2011, 2010 and 2009.