We have operating leases for office space, automobiles and various other equipment in the U.S. and in certain international locations. Other contracts, such as manufacturing agreements and service agreements, are reviewed to determine if they contain potential embedded leases. These other contracts are specifically reviewed to determine whether we have the right to substantially all of the economic benefit from the use of any specified assets or the right to direct the use of any specified assets, either of which would indicate the existence of a lease.

As of September 30, 2022, our operating leases had remaining lease terms ranging from one month to seventy-eight months, some of which included options to extend the leases for up to five years, and some of which included options to terminate the leases within three months. For those leases that are reasonably assured to be renewed, we have included the option to extend as part of our right of use asset and lease liability. Supplemental balance sheet information related to operating leases is as follows:


(In thousands)	Classification	September 30, 2022		December 31, 2021
Assets
Operating lease asset	Other assets	$	28,081	$	4,922
Total lease asset		$	28,081	$	4,922

Liabilities
Current operating lease liability	Accrued expenses	$	6,604	$	1,730
Non-current operating lease liability	Non-current lease obligations		21,490		3,269
Total lease liability		$	28,094	$	4,999

Leases with an initial term of 12 months or less are not recorded on the balance sheet and the lease expense for these leases is recognized on a straight-line basis over the lease term. Lease expense related to these short-term leases was less than $0.1 million for the three and nine months ended September 30, 2022 and 2021, and is included in cost of revenue, selling, general and administrative expenses and research and development expenses in the Condensed Consolidated Statements of Loss. Lease expense related to variable lease payments that do not depend on an index or rate, such as real estate taxes and insurance reimbursements, was $0.2 million and $0.1 million for the three months ended September 30, 2022 and 2021, respectively, and $0.5 million and $0.4 million for the nine months ended September 30, 2022 and 2021, respectively. For lease agreements entered into or reassessed after the adoption of Topic 842, we elected to not separate lease and non-lease components. Our lease agreements do not contain any material residual value guarantees.

The components of lease expense included in the Condensed Consolidated Statements of Loss were as follows:


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(In thousands)	2022		2021		2022		2021
Selling, general and administrative expenses	$	1,444	$	196	$	1,704	$	645
Research and development expenses		228		261		719		815
Cost of sales		20		14		59		38
Total operating lease expense	$	1,692	$	471	$	2,482	$	1,498

As of September 30, 2022 and December 31, 2021, operating lease liabilities included on the Condensed Consolidated Balance Sheets by future maturity were as follows:


(In thousands)	September 30, 2022			December 31, 2021
2022	$	2,209		$	1,767
2023		8,421			1,419
2024		7,098			1,188
2025		5,838			710
2026		3,354			—
Thereafter		5,107			—
Total lease payments		32,027			5,084
Less: Interest		(3,933	)		(85	)
Present value of lease liabilities	$	28,094		$	4,999

Future operating lease payments include $4.5 million related to options to extend lease terms that are reasonably certain of being exercised. There are material legally binding leases that have not yet commenced.

An incremental borrowing rate is used based on information available at the commencement date in determining the present value of lease payments. The incremental borrowing rate is determined on a portfolio basis by grouping leases with similar terms, as well as grouping leases based on a U.S. dollar or Euro functional currency. The following table provides information about our weighted average lease terms and weighted average discount rates:


	As of September 30, 2022
Weighted average remaining lease term (in years)
Operating leases with USD functional currency		1.6
Operating leases with Euro functional currency		4.5
Weighted average discount rate
Operating leases with USD functional currency		3.93	%
Operating leases with Euro functional currency		4.05	%

For the nine months ended September 30, 2022 and 2021, the Company used $2.3 million and $1.4 million of cash in operating activities related to operating leases, respectively.

We are the lessor in sales-type lease arrangements for network equipment, which consisted of the following:


	As of		As of
(In thousands)	September 30, 2022		December 31, 2021
Current minimum lease payments receivable(1)	$	11	$	92
Non-current minimum lease payments receivable(2)		—		4
Total minimum lease payments receivable		11		96
Less: Current unearned revenue(1)		5		70
Less: Non-current unearned revenue(2)		—		1
Net investment in sales-type leases	$	6	$	25

(1)

Included in other receivables on the Condensed Consolidated Balance Sheets.

(2)

Included in other assets on the Condensed Consolidated Balance Sheets.