Irrevocable Waiver of Rights under Exchange Agreement

Exhibit 2.3

IRREVOCABLE WAIVER OF RIGHTS UNDER EXCHANGE AGREEMENT
September 17, 2007

     Reference is hereby made to (1) that certain Exchange Agreement, dated as of January 31, 2007, as amended (the ‘Exchange Agreement”), by and among the Consenting Noteholders (as defined therein), SunCom Wireless Holdings, Inc., a Delaware Corporation (the “Company”), and certain of its Subsidiaries and (2) that certain Agreement and Plan of Merger, entered into on September 16, 2007 (the “Merger Agreement”), by and among Company, T-Mobile USA, Inc., a Delaware corporation (“Parent”), and Tango Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent. If the Merger contemplated by the Merger Agreement is completed, among other things, the company will become a wholly-owned subsidiary of Parent, and each outstanding share of common stock of the Company will be converted into the right to receive $27 per share, in cash, and the former holders of such shares will have no continuing equity interest in the Company.

     The undersigned hereby irrevocably waives any right it might have under Section 9.1 of the Exchange Agreement to designate from and after the Effective Time (should it occur) any person for election to, or to fill any vacancy arising at or after the Effective Time (should it occur) on, the Company’s Board of Directors. The foregoing waiver shall have no effect if the Merger Agreement is terminated in accordance with its terms prior to the Effective Time, but otherwise shall be irrevocable.

Date: 9/17/2007

IRREVOCABLE WAIVER OF RIGHTS UNDER EXCHANGE AGREEMENT
September 17, 2007

     Reference is hereby made to (1) that certain Exchange Agreement, dated as of January 31, 2007, as amended (the ‘Exchange Agreement”), by and among the consenting Noteholders (as defined therein), SunCom Wireless Holdings, Inc., a Delaware Corporation (the “Company”), and certain of its Subsidiaries and (2) that certain Agreement and Plan of Merger, entered into on September 16, 2007 (the “Merger Agreement”), by and among Company, T-Mobile USA, Inc., a Delaware corporation (“Parent”), and Tango Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of parent. If the Merger contemplated by the Merger Agreement is completed, among other things, the company will become a wholly-owned subsidiary of parent, and each outstanding share of common stock of the company will be converted into the right to receive $27 per share, in cash, and the former holders of such shares will have no continuing equity interest in the Company.

     The undersigned hereby irrevocably waives any right it might have under Section 9.1 of the Exchange Agreement to designate from and after the Effective Time (should it occur) any person for election to, or to fill any vacancy arising at or after the Effective Time (should it occur) on, the company’s board of Directors. The foregoing waiver shall have no effect if the Merger Agreement is terminated in accordance with its terms prior to the Effective Time, but otherwise shall be irrevocable.

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IRREVOCABLE WAIVER OF RIGHTS UNDER EXCHANGE AGREEMENT
September 17, 2007

     Reference is hereby made to (1) that certain Exchange Agreement, dated as of January 31, 2007, as amended (the ‘Exchange Agreement”), by and among the Consenting Noteholders (as defined therein), SunCom Wireless Holdings, Inc., a Delaware Corporation (the “Company”), and certain of its Subsidiaries and (2) that certain Agreement and Plan of Merger, entered into on September 16, 2007 (the “Merger Agreement”), by and among Company, T-Mobile USA, Inc., a Delaware Corporation (“Parent”), and Tango Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent. If the Merger contemplated by the Merger Agreement is completed, among other things, the company will become a wholly-owned subsidiary of Parent, and each outstanding share of common stock of the Company will be converted into the right to receive $27 per share, in cash, and the former holders of such shares will have no continuing equity interest in the Company.

     The undersigned hereby irrevocably waives any right it might have under Section 9.1 of the Exchange Agreement to designate from and after the Effective Time (should it occur) any person for election to, or to fill any vacancy arising at or after the Effective Time (should it occur) on, the Company’s Board of Directors. The foregoing waiver shall have no effect if the Merger Agreement is terminated in accordance with its terms prior to the Effective Time, but otherwise shall be irrevocable.

Date: 9/18/2007