Revenues

Site rental revenues

The Company generates site rental revenues from its core business by providing tenants with access, including space or capacity, to its shared communications infrastructure via long-term contracts in various forms, including lease, license, sublease and service agreements. Providing such access over the length of the contract term represents the Company’s sole performance obligation under its site rental contracts.

Site rental revenues from the Company’s contracts are recognized on a straight-line, ratable basis over the fixed, non-cancelable term of the relevant contract, which generally ranges from five to 15 years for wireless tenants and three to 20 years related to the Company's fiber solutions tenants (including from organizations with high-bandwidth and multi-location demands), regardless of whether the payments from the tenant are received in equal monthly amounts during the life of a contract. Certain of the Company's contracts contain (1) fixed escalation clauses (such as fixed-dollar or fixed-percentage increases) or inflation-based escalation clauses (such as those tied to the consumer price index), (2) multiple renewal periods at the tenant's option, and (3) only limited termination rights at the applicable tenant's option through the current term. If the payment terms call for fixed escalations, upfront payments, or rent-free periods, the revenue is recognized on a straight-line basis over the fixed, non-cancelable term of the agreement. When calculating straight-line rental revenues, the Company considers all fixed elements of tenant contractual escalation provisions, even if such escalation provisions contain a variable element in addition to a minimum. The Company's assets related to straight-line site rental revenues include current amounts of $101 million included in "Other current assets" and non-current amounts of $1.4 billion included in "Deferred site rental receivables" for the period ended March 31, 2019. Amounts billed or received prior to being earned are deferred and reflected in "Deferred revenues" and "Other long-term liabilities." Amounts to which the Company has an unconditional right to payment, which are related to both satisfied or partially satisfied performance obligations, are recorded within "Receivables, net" on the Company's condensed consolidated balance sheet.

Services and other revenues

As part of the Company’s effort to provide comprehensive communications infrastructure solutions, the Company offers certain services, primarily relating to its towers and small cells, predominately consisting of (1) site development services and (2) installation services. Upon contract commencement, the Company assesses its services to tenants and identifies performance obligations for each promise to provide a distinct service.

The Company may have multiple performance obligations for site development services, which primarily include: structural analysis, zoning, permitting and construction drawings. For each of the above performance obligations, service revenues are recognized at completion of the applicable performance obligation, which represents the point at which the Company believes it has transferred goods or services to the tenant. The revenue recognized is based on an allocation of the transaction price among the performance obligations in a respective contract based on estimated standalone selling price. The volume and mix of site development services may vary among contracts and may include a combination of some or all of the above performance obligations. Payments generally are due within 45 to 60 days and generally do not contain variable-consideration provisions. The Company has one performance obligation for installation services, which is satisfied at the time of the respective installation or augmentation.

Since performance obligations are typically satisfied prior to receiving payment from tenants, the unconditional right to payment is recorded within "Receivables, net" on the Company’s condensed consolidated balance sheet. The vast majority of the Company's services relates to the Company's Towers segment, and generally have a duration of one year or less.

Additional information on revenues

As of both January 1, 2019 and March 31, 2019, $2.3 billion of unrecognized revenue was reported in "Deferred revenues" and "Other non-current liabilities" on our condensed consolidated balance sheet. During the three months ended March 31, 2019, approximately $110 million of the January 1, 2019 unrecognized revenue balance was recognized as revenue. During the three months ended March 31, 2018, approximately $100 million of the January 1, 2018 unrecognized revenue balance was recognized as revenue.

The following table is a summary of the contracted amounts owed to the Company by tenants pursuant to site rental contracts in effect as of March 31, 2019.



	Nine months ending December 31,		Years ending December 31,
	2019		2020		2021		2022		2023		Thereafter		Total
Contracted amounts ^(a)	$	3,037	$	3,862	$	3,661	$	3,431	$	2,725	$	6,887	$	23,603


(a)	Based on the nature of the contract, site rental contracts are accounted for pursuant to relevant lease accounting (ASC 842) or revenue accounting (ASC 606) guidance.

See note 11 for further information regarding the Company's operating segments and note 9 for further discussion regarding the Company's lessor arrangements.